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International Nannoplankton Association
La Parguera, Puerto Rico • February I 0-13, 1998''"

Seventh International Nannoplankton Association
February 10-14, 1998 *La Parguera, Puerto Rico

* Tuesday, February 10th,1998 *
07:30-08:30

Breakfast at Hotel

08:45-10:00

Workshop (Salon Bahia):
Nannofossil taxonomy and classification - general aspects and 'possibilities
for encouraging consistency in taxonomy
Paul Bown & Jeremy Young

10:00-10:15

Coffee break

10:15-12:15

Workshops (Salon Bahia):
Mesozoic taxonomy revision proposals
Paul Bown & Jeremy Young

Cenozoic taxonomy revision proposals
Jeremy Young & Paul Bown
Living/Quaternary workshop on Syracosphaera/Pontosphaera
Ric Jordan
12:30-13:30

Lunch (on your own)

13:30-15:30

Workshops (Salon Bahia)
M94 filter- implications for estimating coccolithophore abundances
Amos WinterModeling the flux of coccolithophores to the ocean floor
Patrizia Ziveri

13:30-15:30

POSTER SESSION I - (Salon Bahia)

16:00-17:00

Tour of Mangrove Channels

17:00-18:00

Reception, UPR Department of Marine Sciences (Isla Magueyes)

19:00-20:00

Dinner at Hotel* Wednesday, February 11th, 1998 *
7:00-8:00

Breakfast at Hotel

8:00-8:30

Welcoming remarks
Talks session IA - Large scale surveys and projects - (Salon Bahia)
Shirley van Heck & William Siesser presiding

8:30-9:05

Hans R. Thiersten (and others)
Paleobiology of the Pelagic Realm.

9:05-9:40

Peter Westbroek
Modeling Biosphere-Geosphere Interactions.

9:40-10:05

Mario Cachao (and others)
CODENET- An European Research Network to Study Coccolithophorids.

10:05-10:20

Coffee break
Talks session IB - Morphology and taxonomy-(Sal6n Bahia)
Shirley van Heck and William Siesser presiding

10:20-10:45

LluYsa Cros (and others)
New Examples ofHolococcolith-Heterococcolith Combination Cells andtheir implications for Coccolithophorid Phylogeny.

10:45-11:10

Syed A. Jafar
Architecture of Braarudosphaera bigelowii (coccolithophorid): A Marine
Planktonic Alga Holding Clues to Quasicrystalline Symmetry.

11 :10-11:35

Paul Bown (and others)
The Morphology, Classification, Evolution and Morphometries of the Late
Cretaceous Coccolith Genus Gartnerago Bukry, 1969.

11:35-12:00

Jeremy R. Young (and others)
Chirality and the KIT Boundary

12:00-12:25

Andy Howard (and others)
Morphometric Analysis of the Broinsonia parca plexus across the
Santonian-Campanian Boundary.

12:30-13:30

Lunch at HotelTalks session II - Jurassic
Elisabetta Erba and Sherwood Wise presiding

13:35-14:00

Emmanuela Mattioli (and others)
The Eustatic and Climatic-orbital Signature on Phytoplankton andGeochemistry: Examples from the Early Toarcian in Central Italy.

14:00-14:20

Nicola Perilli (and others)
Calcareous Nannofossil Biostratigraphy of Early and Middle Toarcian fromthe Cordillera lberica and Cuenca Vasco-Cantabrica (Spain).

14:20-14:40

Nicola Perilli'\
Early-Middle Toarcian Calcareous Nannofossils of San Andres and Camino
Sections (Cuenca Vasco-Cantabrica, Spain).

14:40-15:05

Elisabetta Erba (and others)
Isotope Fluctuations and Plankton Diversification in the Middle Jurassic ofWestern Tethys.

15:05-15:30

Richard Howe
A Preliminary N annofossil Biostratigraphy of the J urassic of the Ran kin
Platform and Dampier Sub-Basin on the North West Shelf of Western
Australia.

15:30-15:45

Coffee break

15:45-16:30

INA Business Meeting (Salon Bahia)

16:30-18:45

POSTER SESSION 11 _. (Salon Bahia)

19:00

Bus to Chancellor's residence University of Puerto Rico, Mayagiiez

20:00-22:00

Reception and dinner at Chancellor's residence*Thursday, February 12th, 1998*

07:00-08:00

Breakfast
Talks session III- Cretaceous and Palaeogene- (Salon Bahia)
Nicky Hine and Tim Bralower presiding

08:00-08:25

Christianne Street (and others)
Palaeobiology of Early Cretaceous Nannoplankton

08:25-08:50

Fabio Lottaroli (and others)High resolution Biostratigraphy in the North Sea Chalk (Off-Shore
Norwegian North Sea).

08:50-09:15

09:15-09:40

Jeremy R.Young (and others)
Cenomanian Nannofossils and Milankovitch Cyclicity.
mina I.S. Karega~
he Mi~-Late Cretaceous and Early Tertiary Calcareous Nannofossils;
anzama.

U

09:40-10:05

Timothy J. Bralower
Reworked Nannofossils Indicate Margin Collapse and Massive Sediment
Gravity Flows in the Gulf of Mexico and Caribbean Triggered by theCretaceous/Tertiary Boundary Chicxulub Impact

10:05-10:30

Yoram Eshet (and others)
Microfossils Help in Deciphering a Complex Metamorphic andPaleogeographic Enigma.

10:30-10:45

Coffee break

10:45-11: 10

Simonetta Monechi (and others)
Statistical Analysis of Sequential Abundance Data: Paleo-Ecological
Evidence from the Upper Eocene Massignano Section (Central Italy).

11:10-11:35

Tania Hildebrand-Habel (and others)
Variations in South Atlantic Calc-dinoflagellate Associations since theLate Cretaceous.

11:35-12:00

Alyssa M. Peleo-Alampay,
Unusual Oligocene Braarudosphaera-rich Layers of the South Atlantic andtheir Paleoceanographic Implications.

12:00-12:25

Jens Wendler (and others)High Resolution Sequence Biostratigraphy with Calcareous Dinoflagellate
Cysts, Coccoliths and Foraminifera.

12:25-13:25

Lunch at HotelTalks Session IV - Neogene and Quaternary- (Salon Bahia)
Jeremy Young and Jean Self-Trail prd,siding

13:25-13:50

Ting C. Huang
Nannofossils from the lower Miocene of Puerto Rico

13:50-14:15

Richard A. Denne
Calcareous Nannoplankton Dominance Shifts of the Plio-Pleistocene:
Global Significance and Implications for Biostratigraphy.

14:15-14:40

Patrick Sean Quinn
Ceramic Nannopalaeonfulogy

\fvf1CI!N~
14:40-15:05~ Mario Cachao

15:05-15:30

Christine Holl (and others)
On the Environmental Affinity of Calcareous Dinoflagellates in Late
Quaternary Sediments of the Tropical Atlantic.

15:30-15:45

Coffee break

15:45-16:10

31-is-abetta Er-h&.~and-eth~·
Response of calcareous nannofloras to paleoceanographic changes related tosapropels (Late Pleistocene, Eastern Mediterranean).

16:10-16:35

Hanno Kinkel (and e-ther-~
Coccolithophore Response to Changing Late Quaternary Paleoceanography
in the Equatorial Atlantic Ocean.

16:35-19:00

POSTER SESSION Ill- (Salon Bahia)

19:00-20:00

Dinner at Hotel

20:30-23:00

Tropical Rhythm Dance Band - (Salon Bahia)(and others)
Coccolith Palaeoecological Interpretations from an Upwelling Region Off
NW Africa (ODP 658C) During the Last 130 kyrs.

* Friday, February 15th, 1998 *07:00-08:00

Breakfast at HotelTalks session V - Modern nannoplankton, biological oceanography and ecology
Hisatake Okada and Simonetta Monechi presiding(Salon Tropical)
08:00-08:25

Open

08:25-08:50

Richard Jordan (and others)
Seasonal Changes in the Living Coccolithophorid Assemblages off the
Puerto Rican Coast.

08:50-09:15

Mara Cortes (and others)
Coccolithophore Ecology at the Time-Series Station ALOHA, Hawaii.

09: 15-09:40

Britta Karwath (and others)
Environmental Affinities of Thoracosphaera heimii in Field and Laboratory
Studies - Preliminary Results.

09:40-10:05

Hisatake Okada (and others)
Seasonal Variation of Modern Coccolithophores in the Subarctic Pacific
Ocean and Bering Sea.

I 0:05- I 0:30

-Gpen-

10:30-10:45

Coffee break

10:45-11:10

Mario Cachao (and others)(Cocco)liths versus (Cocco)spheres: A Method to Approach the Ecology
and the Biostratonomy of Coccolithophores.

11:10-11:35

Luc Beaufort (and others)
Coccolith Production and Sedimentation in the Vicinity of the NorthWestern African U pwelling.

11:35-12:00

Patrizia Ziveri
Export Production and Preservation of Coccolithophores from Upwellingand Oligotrophic Areas.

12:00-12:30

Yoram Eshet
The Virtual Paleontologist, OR: Children as Real Paleontologists
Lunch - on your own
Afternoon - recover; except CODENET participants who have workshop
session (small conference room).

18:00-19:00

Tour of Phosphorescent Bay with our own Dr. Juan Gonzalez*Saturday/ February 14th/ 1998 *
08:00-15:00 Field trip (includes lunch somewJ.l<:re)POSTER SESSIONS
Tuesday, February lOth, 1998
Wednesday, February 11th, 1998
Thursday, February 12t\ 1998

13:30 - 15:30
16:30 - 18:45
16:35 - 19:00

Pl

DuVernay. Alvin. Biosteering on 'Mars'- Reducing Uncertainties of Horizontal
Drilling.

P2

Antunes, Rogerio Loureiro, Luiz Carlos Veiga de Oliveira. Seirin Shimabukuro and Armando
Scarparo Cunha. Calcareous Nannnofossil Biozones of the Brazilian Continental
Margin: Evolution of a Concept.

P3

Styzen. Michael J. and Terri Dunn. Summary of the Nannofossil Gulf Coast
Equivalency Project.

P4

Siesser. William G. Biostratigraphy ofthe Genus Scyphosphaera.

P5

Hamrsmid. Bohumil and Yawoa da Costa. Calcareous Nannoplankton Biostratigraphyof the Coast Basin of Togo, West Mrica.

P6

Walsworth-Bell. E. Benedict. Paul R. Bown, and Graham P. Weedon. Jurassic Nannofossil
Ecology and Environmental Cycles: Preliminary Results.

P7

Mattioli. Emmanuela and Raffaella Bucefalo Palliani. Lower Jurassic Integrated
Biostratigraphy based on Calcareous Nannofossils and Dinoflagellate Cysts in the
Tethyan Realm.

P8

Burnett. Jackie A., Paul R. Bown, Jeremy R.Young and Jim B. Riding. Phytoplankton
Dynamics and Environmental Cycles in the Late Jurassic Kimmeridge ClayPreliminary Results.

P9

Geisen. Markus Jorg Mutterlose, and Jeremy R. Young. Coccolith Biometrics: A High
Resolution Case Study in the Hauterivian (early Cretaceous) and Planned Work in
the CODENET Project.

PlO Veiga de Oliveira. Luiz Carlos. Rene Rodrigues, Valesca Brasil Lemos, Ricardo Ayup-Zouain,
and Ivanise Maria Wolf£. Multivariate Analysis of Calcareous Nannoplankton andStable Isotopic Study in the Upper Campanian- Lower Maastrichtian of theCampos Basin (SE Brazil).
Pll

Svabenicka. Lilian. Evidence of the Braarudosphaera-rich Sediments in theTuronian of the Bohemian Cretaceous Basin, Czech Republic.

P12 Self-Trail. Jean M. and Gregory S. Gohn. Sequence Biostratigraphy of a Shallow
Marine Environment: Campanian and Maastrichtian Sediments of South Carolina,
U.S.A.
P13

Eshet. Yoram and S. Moshkovitz. Paleocene Calcareous Nannofossil Biostratigraphy in
Israel - Preliminary Results.

P14 Fukasawa. Kazue and Chikara Hiramatsu. Biostratigraphic and Paleoceanographic
Significance of the Late Middle Miocene- Early Pliocene Calcareous Nannofossils

from the Coast of the Sea of Japan, Northeast Japan.
P15

Peleo-Alampay. Alyssa M. Miocene Calcareous Nannofossil Magnetobiostratigraphy
and Biochronology.

P16 Huang, Ting C. Nanno~ossils from a Lower Miocene Core of Puerto Rico.
Pl7 Villa. G. and Wise, S. Quaternary and Miocene Thoracosphaera in the Ross Sea (77 o S
Latitude).
PIS Baumann. Karl-Heinz, Hanno Kinkel, Martin Cepek, and P.J. Miiller. Coccolithophoreand Alkenone Changes in Late Quaternary Sediments of the South
Atlantic.Miocene - Pliocene'

P19 Lototskaya Anna, Patrizia Ziveri, Gerald M. Ganssen, and Jan E. van Hinte. Calcareous
Nannoflora Response to Termination 11 at 45 °-53°N (Northeast Atlantic).
P20 Tanaka. Yuichiro. Late Quarternary Nannofossil Assemblages in the Transitional
Northwestern Pacific Ocean.
P21 Hine. Nicky. Variations in Surface Water Mass Conditions Along the North East
Atlantic Fringe as Evidenced by Late Quaternary Calcareous N annoplankton.
P22 Flores. Jose-Abel, F. Javier Sierro, Caries Pelejero, Joan Grimalt, Luejiang Wang andMichael Sarnthein. Sea Surface Dynamics and Paleomonsoon Variability in theSouth China Sea for the Last 140,000 Years.
P23

Flores. J.A., Barcena, M. A. and Sierro, J. F. Trade-Wind Effect in the Sea Surface
Dynamic OffWest-Africa (5 oN) During the Last Climatic Cycle.

P24 Esper. Oliver, Karin Zonneveld and Helmut Willems. Palaeoceanological reconstructionof the Late Quaternary Agulhas Current (South Atlantic) Based on Calcareous andOrganic Walled Dinoflagellate Cysts.
P25

Ziveri. Patrizia, Arrian Rutten, Cesare Corselli, and Gert de Lange. Coccolith CaCO 3 Actuo
and Paleo-fluxes from the Eastern Mediterranean.

P26

Zeltner. Alexandra. Coccolith fluxes in the central Arabian Sea. (14 °27,46'N, 64 o
34,32'E).

P27 Henderiks, J, J. Bollmann, T. Freudenthal, H. Meggers, C. Sprengel, and H.R. Thierstein.
Coccolith Assemblages Along anE-W Transect North of the Canary Islands (29 oN):
Comparison Between Sediment, Sediment Trap and Plankton Samples.
P28 Broerse. Alexandra T. C. Coccolithophore (CaCO 3 ) Fluxes in the Sea of Okhotsk(North Pacific Ocean).
P29 Broerse. Alexandra, T.C. Coccolithophore Export Production from Equatorial to SubPolar Waters.
P30 Andruleit. Harald. Coccolithophore Sedimentation in the Nordic Seas: Findings fromThree Trap Moorings.
P31 Baumann, Karl-Heinz, and Sprengel. Claudia. Seasonal and Interannual Variations ofCoccolithophore Fluxes and Species Composition in Sediment Traps North of the
Canary Islands.
P32 Baumann, K.H .. H. Andruleit, and C. Samtleben. Coccolithophores of the Nordic Seas:
Comparison of Living Communities with Surface Sediment Assemblages.
P33 Baumann, Karl-Heinz. Variations in Morphometry of Coccolithus pelagicus
Coccoliths in Plankton and Sediments of the Northern North Atlantic.
P34 Vink. Annemiek. Karin Zonneveld and Helmut Willems. Recent Distributions ofCalcareous Dinoflagellates in the South Atlantic and Their Potential Use in
Palaeoecology.
P35

Cros, Llui:sa. Variety of Exothecal Coccoliths of Syracosphaera.

P36 Bollmann, Jorg, Hans Barth, Michaela Knoll, Bernd Lenz, Federico L6pez Laatzen, Thomas
Mi.iller, Rainer Reuter, Gerold Siedler, Andrea Spies, Claudia Sprengel, Hans R. Thierstein.
Oliver Zielinski Distribution of Living Coccolithophores Along a Zonal Transect(29°N) North of the Canary Islands: Vertical, Seasonal and Interannual Variations.
P37 Hagino. Kyoko. Community Structure of Living Coccolithophore in the Central andWestern Pacific.
P38 Hernandez-Becerril. ! avid Uriel. Cocolithophorids from the Subtropical Mexican
Pacific (West Coast ofBaja California, Mexico).
P39 Takahashi. Kyoma. Modern Nannoflora from off the Coast ofWestern Australia.
P40 Westbroek, Peter, Bas Kooijman, Jan van Hinte, Patrizia Ziveri. Geobiology, Definition,
Organization and Some Representative Research.

Late Pleistocene-Holocene Palaeoclimatic Changes As Recorded
By Caclcareous Nannofossils (Central Tyrrhenian Sea- Italy)
Filomena Omella Amore and Paola Esposito
Dipartimento di Scienze della Terra
Universita di Napoli "Federico II" Largo San Marcellino, 10- 80138 NAPOLI, ITALY
E- mail: amore@unina.it

A quantitative analysis of the calcareous nannofossil assemblages from three Late
Pleistocene-Holocene gravity cores from the Gaeta Bay continental shelf (Central TyrrhenianSea-Italy) was done. The core CS (SOO cm long, 111 mbsl, 41 °0S'41 "N; 13°3S'S6"E) consists of twounits separated by a discontinuity surface. The more distal cores C8 (362 cm long, 126 mbsl,
41 °04'31 ''N, l3°32'18"E) and C9 (470 cm long, 212 mbsl, 41 °02'46"N, l3°29'24"E) present a
continuous sedimentary record. The analysis of the acoustic profiles (Senatore, 1996) identified a
prograding wedge system with clinoforms increasing in dip seaward. Thus, the lower interval in
the CS is older than in the other cores. The interpretation of seismic profiles is also supported bynannofossils data: the Emiliania huxley Acme and E. huxley Zones (Gartner, 1977) have been
identified in core CS. The boundary between the zones is at 270 cm. To detect this event thequantitative counting method ofRio et al., 1990 has been adopted. The C8 and C9 cores lower
intervals should correspond to stage 2 partim. The upper parts of all the cores represent the Late
Glacial-Holocene intervals. The quantitative analysis of the calcareous nannofossils assemblages
was focused to recognize the Late Pleistocene- Holocene palaeoclimatic patterns of this area.

In this study in agreement with the climatic and palaeoclimatic meaning of
coccolithophore R. clavigera, U sibogae, C. leptoporus and Pontosphaera spp. have been
considered warm species, instead C. pelagicus has been considered a cold water indicator.
However in our cores we observed that C. leptorus and C. pelagicus are controlled also by
nutrient enrichment. A palaeoclimatic curve using a formula already utilized for foraminifera wasdone. The basal units of all the cores correspond to episodes characterized by high percentages ofC. pelagicus and by low percentages ofthe warm water species. A first increase of the warm taxa
and a dramatic drop of C. pe/agicus at the base of Late-Glacial interval have been observed.
During this interval maximum value of B. bigelowi has been recorded. This species is generally
absent or represented with very low percentages in our cores. However peaks of abundance, withmaximum value in the nearshore cores, occur in all cores during this period and could suggestthat the abundance of this species be linked to major wet and increased regional rainfall andrunoff of this period. The YD is characterized by a slight decrease of warm waters species, aparallel increase in cold waters species and by some barren levels that show instead diatom
blooms. The Holocene/Pleistocene boundary is characterized by low values of C. pelagicus, by afurther increase of U sibogae, Rhabdosphaera spp., by a dominance of E. huxley and an increase
of Ceratolithus spp. Peaks of C. leptoporus and H. carteri are observed during the Holocene.
Flores et al. (1997) recorded "maxima in the abundance ofthese taxa during interglacial periods".
Pujos (1992) suggest that the higher values of these species may be linked to nutrient-rich waters.
In our cores a relationship between peaks of these taxa and peaks of C. pelagicus has been
observed. This species prefers cold water but also high concentration in nutrient (Cachao &Moita 199S; Roth 1994). Syracosphaera spp. have been recorded in the cores and they occur

more frequently and with higher percentage in the Holocene part of the cores. Peaks inabundance of Ceratolithus spp. are also observed in all the cores. We observed that maximum
value of Ceratolithus spp. is always associated with peaks of R. c/avigera and maximum value ofGlobigerinoides spp (Amore et al., in press), which could testify a further warming within the
Holocene.
REFERENCES
F.O. AMORE, G. CIAMPO, V. DI DONATO, P. ESPOSITO, E. RUSSO ERMOLLI AND D. STAITI. An
integrated micropalaeontological approach applied to Late Pleistocene-Holocene palaeoclirnatic andpalaeoenviromnental changes (Gaeta Bay, Tyrrhenian Sea) Geol. Soc. Spec. Publ., (Submitted).
CACHAO, M. & MOITA, M.T. 1995. Coccolithus pelagicus a sort of productivity proxy? 6th International
Nannoplankton Conference in Copenhagen Abstract, 33-34.
FLORES, J.A., SIERRO, F.J., FRANCES, G., VASQUEZ, A. & ZAMARRENO, I. 1997. The last 100,000 years in
the western Mediterranean: sea surface water and frontal dynamics as revealed by coccolithophores.
Marine Micropaleontology, 29, 351-366.
GARTNER, S. 1977. Calcareous nannofossil biostartigraphy and revised zonation of the Pleistocene. Marine
Micropaleontology, 2, 1-25.
PUJOS A., 1992. Calcareous nannofossils ofPlio-Pleistocene sedirnents from the northwestern marginoftropical
Africa. In: C.P. Summerhayes, W.L. Prell and K.C. Emeis (eds.), Upwelling Systems: EvolutionSince the
Early Miocene. Geol. Soc. Spe. Publ., 64, 343-359.
RIO, D., RAFFI I. & VILLA, G. 1990. Pliocene-Pleistocene calcareous nanofossil distribution patterns in thewestern Mediterranean. Proc. Ocean Drilling Project, 107, 514-5 31.
ROTH, P.H. 1994. Distribution of coccoliths in oceanic sediments. In: Coccolithophores Winter A. & Siesser W.
(eds), 199-218.
SENATORE, M.R. 1996. Cicli eustatici diNe V ordine in depositi del Pleistocene medic superiore-Olocene delGolfo di Gaeta (Mar Tirreno). Atti della Riunione del Gruppo di sedimentologia del CNR. Catania 10-14
Ottobre 1996, 242-244.

Coccolithophore Sedimentation in the Nordic Seas:
Findings from Three Trap Moorings
Harald Andrulejt

Bundesanstalt fiir Geowissenschaften und Rohstoffe (BGR),
Stilleweg 2, 30655 HANOVER, GERMANY. e-mail: h.andruleit@bgr.de(formerly at Sonderforschungsbereich 313, University ofKiel)

Coccolithophore fluxes were investigated by sediment trap studies at three sites in theNordic Seas from 1990 to 1992 and 1994 to 1995. Each trap mooring comprised traps at threedifferent water depths: at 300 to 500m, at 1OOOm water depth, and about 300m above theseafloor. All sites were characterized by a strong seasonality in coccolithophore fluxes. Highest
fluxes were observed in the Norwegian Sea (NB 6) which were about 10 to 20 times higher thanin the southern Greenland Sea (OG 4/5). Interestingly fluxes from the central Greenland Sea (GS2) were lower than in the Norwegian Sea but clearly higher than in the southern Greenland Sea.
Maximum fluxes (13x10 6 ind.m-2d- 1 for the Norwegian Sea, 2.4x106 ind.m-2d- 1 for the southern
Greenland Sea, and 12x106 ind.m-2d- 1 for the central Greenland Sea) were reached during highsedimentation phases in late summer and autumn.
The settling assemblages represented already highly altered remnants of the former living
communities. However, only in the central Greenland Sea (GS2) dissolution seemed to be ofmajor influence. Dominant species were Emiliania huxleyi in the Norwegian Sea andCoccolithus pelagicus in the Greenland Sea. Especially in the central Greenland Sea C. pelagicus
dominated with more than 98%. Clear differences in the assemblage compositions are thought toreflect distinct signatures of the local oceanography.
The settling assemblages underwent only minor alterations during sinking from 500 to
1OOOm water depth. By contrast, resuspension and lateral advection wit~n an extensive bottom
nepheloid layer strongly influenced the assemblages of the deep sediment traps 300m above theseafloor, wiping out the distinct seasonality in coccolithophore fluxes and diminishing thedifferences in assemblage compositions between the three sites.

Calcareous Nannnofossil Biozones of the Brazilian Continental Margin:
Evolution of a Concept
Rogerio Loureiro Antunes, Luiz Carlos Veiga de Oliveira, Seirin Shirnabukuro andAnnando Scarparo Cunha
PETROBRAS/CENPES/DIVEX/SEBIPE, Pd. 20, Cid. Universitfui.a, Quadra 7, 21949-900,
RIO de JANEIRO, RJ, BRAZIL. E-mail: lcveiga@cenpes.petrobras.com.br.

In Brazil, the biostratigraphic research on the calcareous nannoplankton began in 1968,
during the early phase of petroleum exploration on the continental margin. These initial studies
lent support to the first biozonation, by Troelsen & Quadros (1971), comprises 22 biozones (5 ofwhich in the Cretaceous and 17 in the Cenozoic). Subsequent research aimed at more precise age
determinations ofthe biozones and more refined biostratigraphic frameworks. In 1993, Ricther
et al. integrated all previous work in the Cenozoic section of the Brazilian continental margin andproposed a new biozonation. This scheme is nowadays in use and consists of35 interval zones
defined by last .occurrences of selected taxons. Concerning the Cretaceous section, additional
studies have provided the basis for an improved biozonation. Antunes (in press) criticallyreviewed all zones proposed until then for the Mesozoic section of the continental margin andconstructed a preliminary biozonation to be tested in further investigations. This biostratigraphic
framework has ever since been approved in the Sergipe/Alagoas, Potiguar, Santos and Campos
basins. In 1997, new biozones were added to Cretaceous zonation of the Campos and Santos
basins (Oliveira, 1997; Oliveira & Costa, 1997).

It has been demonstrated that Albian biozones differ markedly on the equatorial andsoutheast margins. Probably, this results from distinct oceanographic conditions prevalent during
early developmental phases of the South Atlantic Ocean.

Isotope Fluctuations and Plankton Diversificationin the Middle Jurassic of Western Tethys
A. Bartolini 1, E Erba 2 and E. Mattioli 3
12

Institut de Paleontologie et Geologie, Universite de Lausanne, LAUSANNE - SWITZERLAND
Dipartimento di Scienze della Terra, Via Mangiagalli, MILANO- ITALIA. E-mail: Erba@imiucca.csi.unimi.it
3
Dipartimento di Scienze della Terra, P.za Universita, PERUGIA- ITALIA

An integrated biostratigraphy (calcareous nannofossils and radiolarians) and isotope
stratigraphy study has been carried out in the Umbria-Marche-Sabina (central Italy) and Digne
area (southern France), in the Aalenian to early Bathonian, with the aim to better understand thepalaeoceanographic evolution of the western Tethys during this period. This integrated
stratigraphycal approach has also allowed a better age determination in lithotypes, such as incentral Italy, depleted or barren of ammonites. Although the absolute o13 C values of the Digne
marly limestones are offset by about 1%o with respect to the Umbria-Marche-Sabina pelagic
limestones, all major isotopic shifts can be correlated between the two areas. The 13 C curves
show a relative minimum in the upper Aalenian and a positive composite peak in the upper partof lower Bajocian-lower part of upper Bajocian interval.

oAt the Aalenian!Bajocian boundary a turnover of calcareous nannoplankton can beobserved: the taxa characteristic of the early Jurassic, and mainly Schizosphaerella spp., tend to
decrease in abundance, and W atznaueriaceae experienced a speciation event becoming thedominant taxon in the assemblage. This speciation marked the end of the "Schizosphaerella spp.
age" (Noel et al, 1996) lasting the whole early Jurassic, and led to a long period ofWatznaueria
dominance, before the Nannoconus attain a lithogenetic importance in the terminal Jurassic. The
diversification trend of the Family Watznaueriaceae parallels the 13 C increase. Radiolarianassemblages followed partly the same trend as nannoplankton. From the base of the Bajocian, theradiolarian associations show a slight tendency towards the diversification, coincident withincreasing o13 C values. In the upper part ofthe early Bajocian, Last Appearances prevail overFirst Appearances associated with the peak of the o13 C event. This may indicate maximum
eutrophic conditions. Contemporaneously with the isotopic event, an increase ofbiosiliceous
productivity is recorded as an increase in visible chert in the Umbria-Marche area. The plankton
diversification, the isotope event and the increase in biosiliceous sedimentation may be related todeep palaeoenvironmental modification, such as climatic-eustatic changes, crisis of carbonate
platforms, volcanism, modifying the ocean chemistry and opening new available niches for theplankton.

oVariations in Morphometry ofCoccolithus pelagicus Coccoliths in Plankton and Sedimentsof the Northern North Atlantic
Karl-Heinz Baumann

FB Geowissenschaften, Universitat BREMEN, GERMANY.
E-mail: khb@mail.sedpal.uni-bremen.de.

Variations in the intra-specific morphometry of Coccolithus pelagicus (Wallich) Schiller
were observed in late Pliocene/Pleistocene sediments of the North Atlantic and Nordic Seas. In
general, the distal shield of C. pelagicus show a wide range of size variations, typically 8-16 1-1m
in length and 6-141-Lm in width. Element count for the distal shield is 30-65. Length, width, andthe number of distal shield elements are strongly correlated to each other. Investigation ofplankton samples and surface sediments show that a decrease in mean size of the distal shields
occurs towards the north with approximation to colder surface waters. C. pelagicus distal shieldvariation is much greater in the North Atlantic than observed in the Norwegian-Greenland Sea. In
sediments ofthe Fram Strait small coccoliths (7-121-Lm) were exclusively observed. Thus, surface
water temperature seems to be the primary control for the decrease in mean C. pelagicus size.
This species is a major component of high latitude assemblages although it occasionallyoccurs at much lower latitudes. Fluctuation in morphometry of C. pelagicus therefore areconnected with variations in abundance. The coccolith assemblages in these sediments have been
drastically influenced by glacial-interglacial climatic changes, especially in the Nordic Seas.
However, several abundance peaks are present in the last 3.0 Ma. Most obvious are high numbersof C. pelagicus in sediments of the early Pleistocene, of part of oxygen isotope stage 7, and of the
Holocene. Within all of these intervals an obvious (and drastic) decrease in size was observed,
with coccoliths smaller than 101-1m virtually appearing and longer specimens decreasing inabundance.
Coccolith size probably results from the interaction between coccolith biosynthesis andenvironment. Thus, variations in coccolith-size and abundance of C. pelagicus are due toecological differences in the various interglacials, i.e. due to differences in the inflow of warm
North Atlantic surface water. However, other factors such as nutrients/trophic level could also
control assemblage variation and/or intraspecific variations rather than temperature alone.

Coccolithophores of the Nordic Seas: Comparison ofLiving Communities with Surface
Sediment Assemblages
K -H Baurnann 1, H. Andruleif, and C. Samtleben3
FB Geowissenschaften, Universitiit BREMEN, GERMANY.
E-mail: khb@mail.sedpal.uni-bremen.de; h.andruleit@bgr.de

Coccolithophores in the Norwegian-Greenland Sea have been investigated in both a highnumber of plankton samples of several cruises and in surface sediments of the entire area. Here,data of the living communities are compared with results of surface sediment assemblages. The
distribution and frequency of individual species that are found in the surface sediments areshown in biogeographic maps. Living coccolithophore communities in the Norwegian-Greenland
Sea can be classified in three regional groups tracing the corresponding surface water masses:(1) an Atlantic group, (2) an Atlantic-Arctic group, and (3) an Arctic group. These assemblages
are decomposed and altered during descent in the water column. Destruction and solution ofdelicate heterococcoliths and of all the holococcoliths leave only few species at deeper waterlevels. These species are further influenced by differential dissolution and destruction at the
sediment-water interface. As a result, the original composition of the living communities
becomes increasingly obscured in the impoverished taphocoenoses. Samples from surface
sediments contain significantly less coccolithophore species than those which are included inliving communities of the same area. Ofthe identified 22 species in the surface waters only 7 arefound in the surface sediments. The most frequently occurring species are Emiliania huxleyi andCoccolithus pelagicus. In addition, Calcidiscus leptoporus and Gephyrocapsa muellerae areregularly found in small amounts. This becomes even more remarkable when one consider thefact that these species are rarely found in the living communities. Based on the concentration anddiversity of the species and the ratio changes between E. huxleyi and C. pelagicus it is possible toestablish biogeographic zones. Thus, the coccolith distribution in surface sediments of theNorwegian Sea seems to give a good description of the various locations of various water masses
in the area.

Coccolithophore and Alkenone Changes in Late Quaternary
Sediments of the South Atlantic
Karl-Heinz Baumann, Hanno Kinkel, Martin Cepek, and P.J. Muller
FB Geowissenschaften, Universitat BREMEN, GERMANY.
E-mail: khb@mail.sedpal.uni-bremen.de; hkinkel@mail.sedpal.uni-bremen.de.

Late Quaternary coccolithophore assemblages in three sediment cores were investigatedto reconstruct changes in the surface water conditions and productivity. However, variations in
the coccolithophore assemblages give only relative temperature changes. Thus, variations in
species composition are compared to alkenone concentrations and alkenone-derived sea-surface
temperature (SST) records. These SST estimates are usually based on a UK37'-temperature
relationship which was quantified using data from clonal cultures of Emiliania huxleyi. Therefore
this cosmopolitan species is believed to be the main producer of alkenones in the open ocean.
Meanwhile it was shown that Gephyrocapsa oceanica synthesizes alkenones and it is believedthat other species of Gephyrocapsa should also contain this biomarker. Nevertheless, SSTs
derived from UK3 7' relationship may be biased if other coccolithophores with different
temperature affinities have contributed to the sedimentary alkenone record. Therefore, in thepresent study, we focused on the correlation between occurrence and abundances of the mostabundant species with both the normalized alkenone concentration as well as SSTs. It is,however, not yet proofed whether all of these species actually produce alkenones. By simply
plotting the alkenone concentrations against the coccolith abundances of the dominant species,
only few trends are apparent in the scattergrams. Carbon-normalized alkenone concentrations areinversely correlated to abundances of E. huxleyi. In contrast, abundances of Gephyrocapsa
oceanica and of G. ericsonii (but not of G. muellerae) are directly related to normalized alkenone
concentrations. Numbers and abundances of most ofthe other species do not correlate to thealkenone data. However, although abundances of Gephyrocapsa species best fit to alkenone
concentrations, the calibration made by E. huxleyi yield the more reasonable SSTs even for
periods when this species was absent from the record. In addition, the correlation of coccolithabundances to SSTs also give some general trends. Abundances of G. ericsonii and U. sibogae
clearly show a correlation with increasing SSTs, while those of G. muellerae, G. oceanica, andC. leptoporus show a positive trend with cooler temperatures. In general, highest numbers of
coccoliths in the sedimentary record are observed during relatively cold periods and mostprobably are indicative of relatively nutrient-rich waters.

Seasonal and Interannual Variations of Coccolithophore Fluxes and Species Compositionin Sediment Traps North of the Canary Islands
Karl-Heinz Baumann and Claudia Sprengel.
FB Geowissenschaften, Universitat BREMEN, GERMANY.
E-mail: khb@mail.sedpal.uni-bremen.de

The present investigation is part of the MAST Ill target program CANIGO (CanaryIslands Azores Gibraltar Observation), subproject "Particle flux and Paleoceanography in the
Eastern Boundary Current System". One of the main goals of this subproject is to quantitatively
determine the influence of environmental variability on the magnitude and composition ofseasonal and interannual particle flux in the Canary region, and to study the modification ofparticulate matter in the water column. At present, coccolithophore fluxes were investigated in
sediment traps of the time-series station ESTOC (European Station for Time-series in the Ocean,
Canary Islands), located 100 km north off Gran Canaria in the eastern subtropical North Atlantic
gyre. The 20 cup particle traps (AQUATEC) were deployed at 1000m and 3000m below sea
surface. The sampling intervals ranged from one to three weeks.
Results of four mooring intervals from April1993 to October 1995 are presented. Total
coccolithophore flux and the vertical flux of different species at various depths as well as theseasonal trend in species composition are shown. In general, coccolith and coccosphere fluxes(up to 5x109 Ind./m2/day) are characterized by a relatively strong seasonality, and maximum
fluxes were reached during spring time. Emiliania huxleyi was the dominant species during mostof the investigated time interval, followed by Florisphaera profunda and Gephyrocapsa
ericsonii. Considerably higher fluxes observed in the lower traps (-1 OOOm) in comparison to theupper ones (-3000m) are most probably due to lateral advection ofparticulate matter to themooring location. Coccolithophore-CaC03 fluxes were calculated to determine the contribution
to the total biogenic CaC0 3 flux.

Coccolith Production and Sedimentation in the Vicinity of theNorth-Western African Upwelling
Luc Beaufort, Dollfus, D., Buchet, N., and Bieda, S.
CNRS-CEREGE, BP80 13545 Aix-en-Provence cedex 4 FRANCE
E-mail: beaufort@cerege.fr

During the EUMELI experiment (JGOFS France) 6 sediment traps were deployed at two
mooring sites off the Mauritania margin from February 1991 to November 1992. They provided
time series of sedimentation at 3 different depths (250, 1000, 2500 m) with a time resolution
ranging from 8 to 10 days for almost two years in both an oligotrophic area (21 °N 31 °W at about
2000 km from shore) and a mesotrophic area, in the vicinity of the Cap Blanc upwelling (18° N
21 o W). We estimated coccolith, coccosphere and thoracosphere fluxes and compared theseresults to mass, organic carbon, terrigenous and carbonate fluxes. The coccolith contribution to
the CaC03 flux has been estimated.
In the mesotrophic zone the coccolith fluxes range from 51 106 to 10 109 coccoliths m-2
d-1 whereas they range from 23 106 to 179 106 coccoliths m-2 d-1 in the oligotrophic zone. In
the mesotrophic zone coccolith, coccopsphere and mass fluxes are highest during two short
events in March and May 1991. Emiliania huxleyi represents 95% of the coccolithophore
assemblages during these two events, while in the rest of the series the relative abundance of E.
huxleyi is lower. These two events are recorded at the three depths in almost perfectsynchroneity, implying sinking speed higher than 500 m d-1 which is particularly high. At 2500
m the percentage ofCaC03 due to coccoliths is high (about 85%) during these events, sharply
decreases thereafter down to values around 40% and latter progressively re-increases. These
decreases are possibly due to post bloom grazing.
In the oligotrophic zone fluxes are also closely related to total mass flux. The flux
variations of rare species such as Thocosphaera heimii or Ceratolithus cristatus also follow massflux variations. We discuss the different possibilities of production/sedimentation which could
explain such relation and in particular those linked to biological aggregation.

Distribution of Living Coccolithophores Along a Zonal Transect (29°N) North of the CanaryIslands: Vertical, Seasonal and Interannual Variations
Jorg Bollmann 1, Bans Barth2, Michaela K.no11 3, Bemd Lenz\ Federico Lopez Laatzen 4, Thomas Miille~,
Rainer Reuter, Gerold Siedle~, Andrea Spies5, Claudia Sprenge1 5, Bans R Thierstein\ Oliver Zielinski 2!Geological Institute, ETHZ, 8092 ZURICH, SWITZERLAND. E-mail: thiersten@erdw.ethz.ch2
Physics Faculty, University of OLDENBURG, GERMANY
3
lnstitute of Marine Research, Kiel University, KIEL, GERMANY
4
1nstituto Espafiol de Ciencias de Mar, SANTA CRUZ de TENERIFE y MADRID, SPAIN
5
Geoscience Department, University ofBREMEN, GERMANY

The production and burial of calcitic coccoliths in upwelling and oligotrophic ocean areas isstill poorly known, despite the potentially important role they may play in the global carbon cycle.
We are analyzing their production along a pronounced E-W fertility gradient in the Canary Current
system, as a contribution towards assessing their role in the geosphere-biosphere system. Our
general scientific goals are (a) to obtain a better understanding of the seasonal and interannualinteraction between coccolithophores and the physical and chemical environment and (b) to compare
this interaction with the long-term variability of coccolith composition and flux into the sedimentaryarchives.
Towards this general goal cell density and taxonomic composition ofliving coccolithophore
associations were analyzed along an East-West temperature and productivity gradient in the North
Atlantic Eastern Boundary Current at three locations near the mooring stations LP 1 (29° 45. 7N, 17°
57.3W), JGOFS Time-series Station ESTOC (29°10.0N, l5°30.0W) and EBC2 (28°42.5, 13°9.3W).
At these stations, water samples taken at 11 different water depth levels (0-300m) during several
seasonal cruises from September 1995 to September 1997 were filtered on Nucleopore® membranes
in order to determine coccolithophore cell densities and taxonomic composition of the assemblages.
In addition, in situ CTD and fluorometer measurements were done and samples for nutrient andoxygen content were collected from the same water depth levels at all stations.
The strongest gradient in sea surface temperature and salinity along the zonal transect
occurred during late summer (September) and ranged from 24°C and 37.1psu at station LPI to about
20.2°C and 36.5psu at station EBC2. The weakest gradient occurred during winter (January) andranged from 19.5°C and 36.8psu at station LP1 to 19. 1°C and 36.7psu at station EBC2.
Total coccolithophore cell densities showed a strong gradient from the open ocean location
LPl(- 20'000 cells/1) to the near-shore location EBC2 (- 65'000 cells/1) during winter as well as
during late summer (- 18'000 cells/1 to - 45'000 cells/1). Maximum cell densities usually occurred in
the upper photic zone above the deep chlorophyll maximum which was generally located between 50
and 125m water depth.
Five coccolithophore species dominated all assemblages analysed so far. The most abundantspecies was G. ericsonii which dominated the upper photic zone during the whole year at the nearshore station EBC2. At the open ocean station LPl and ESTOC G. ericsonii was the most abundantspecies only from Om to 50m during winter and from 50m to 1OOm during late summer. U tenuis
dominated only during late summer from 0 to 50m water depth at LPl and ESTOC and is of minor
importance at the EBC2 station. Florisphaera profunda is the third most abundant species during all
analysed seasons at all stations below the deep chlorophyll maximum. Emiliania huxleyi was only
found to dominate from 50 to lOOm during winter time at the open ocean stations LPl and ESTOC.

The Morphology, Classification, Evolution and Morphometries of the Late Cretaceous
Coccolith Genus Gartnerago Bukry, 1969
Paul Bown 1, Matthew Hampton2 and Jackie Burnett 1
1

Department of Geological Sciences, University College London, Gower Street, London, WClE 6BT, UK.
Email: p.bown@ucl.ac.uk; j.burnett@ucl.ac.uk
2
Network Stratigraphic Consulting Ltd., Cranbourne Road, Potters Bar, EN6 3DQ, UK

The Cretaceous family Arkhangelskiellaceae has recently been revised (Bown and
Hampton in Bown and Young, 1997: JNR, 19/1, p. 32) following re-evaluation ofthemorphology and phylogeny of the genus Gartnerago (and closely allied Kamptnerius). An
order-level grouping, the Ark.hangelskiales, has been proposed incorporating two families, theKamptneriaceae and Ark.hangelskiellaceae sensu stricto. The rationale behind this revision will
be discussed.
The new order incorporates typically tiered 'placolith' coccoliths, with 3-5 closely
appressed 'shields' and central-area structures which include transverse bars with proximal net;
axial or sub-axial crosses with proximal net; and perforate plates crossed by axial or sub-axial
sutures. The two families, however, display significant variations in light-microscope
appearance, from predominantly dark images in the Kamptneriaceae, to predominantly brightimages in the Arkhangelskiellaceae. The phylogeny of the Kamptneriaceae also appears to be
distinct from the Arkhangelskiellaceae, and incorporates a number of complex and interesting
morphological innovations. The oldest Kamptneriaceae representatives actually possess loxolith
rim morphologies, although in a somewhat modified form. Albian to early Cenomanian species
retained this rim structure, and it was not until the appearance of G. segmentatum (G. obliquumof many authors) that the typical multi-shielded 'ark.hangelskiellid' rim structure was developed.
In fact, this rim structure is not strictly placolith (i.e. discrete, subhorizontal shields separated bya tube), but rather a modified loxolith structure in which folding of the rim-wall produces
shield-like protrusions. While this rim morphology evolution substantially modifies the surficalappearance of the rim (from loxolith-like wall to placolith-like shields) the LM appearance(reflecting the crystallographic architecture) remains remarkably constant.
We will also present the results of a morphometric study of Gartnerago, which has aided
taxonomic clarification and provided useful biostratigraphic information.

Reworked Nannofossils Indicate Margin Collapse and Massive Sediment Gravity Flows in
the Gulf of Mexico and Caribbean Triggered by the Cretaceous/Tertiary Boundary
Chicxulub Impact
Timothy I Bralower
Geology Dept., University of North Carolina, Chapel Hill, NC 27599, USA
bralower@email.unc.edu

Detailed biostratigraphic and lithologic investigations were conducted on Cretaceous/
Tertiary boundary (KTB) sections in eleven Deep Sea Drilling Project and Ocean Drilling
Program sites ranging from the Yucatan continental margin to the Caribbean Sea. In several
sites, a mixture of older, reworked nannofossil assemblages are found with late Maastrichtiannannofossil taxa (e.g., Micula murus and Lithraphidites quadratus). Reworked assemblages
contain markers that are diagnostic of the late Campanian to early Maastrichtian (Aspidolithus
parcus subsp. parcus, A. parcus subsp. constrictus, Eiffellithus eximius, Quadrum gothicum, Q.
trifidum, Reinhardtites anthophorus, R. levis, Lithastrinus grillii, and Tranolithus orionatus), andBarremian to earliest Aptian (Nannoconus steinmannii, N elongatus, N minutus, and Hayesites
radiatus). Some ofthese sites also contain a combination oflate Maastrichtian and older
planktic foraminifers. Pervasive reworking and winnowing, and the paucity of pelagic sediment
components complicates the identification of the KTB level from biostratigraphic data which can
only provide maximum ages in some cases and minimum ages in others. Because a suite offacies and a considerable thickness of sediments may be related to the KTB impact, we use
impact-derived materials (including spherules, shocked quartz and Ir anomalies) to identify KTB
units.
Angular polymict clasts and fining-upwards sedimentary structures indicate that KTB
deposits were laid down by sediment gravity flows, including turbidity currents and debris flows.
In several sites where KTB sediments are missing, there is a distinct unconformity between
Cretaceous and lowermost Paleocene sediments. Scouring by the gravity flows appears to be
responsible for the hiatus at these sites. The reworked nannofossils and lithologically-distinct
clasts suggest the gravity flows were initiated by massive collapse of surrounding continental
margins presumably as a result of the Chicxulub impact. The gravity flow deposits are aeriallyextensive and vertically expansive. Sites up to 1000 km from a potential gravity-flow source
contain the same reworked nannofossil taxa in the KTB deposits as observed in more proximal
sites. Presence of reworked deposits on Cretaceous topographic highs shows that the gravity
flows engulfed a significant part of the lower water column as they moved down slope. Because
thick sequences of reworked KTB sediments were rapidly deposited (in hours to a few years),strict use of traditional biostratigraphic techniques yields erroneous age interpretations.

Coccolithophore Export Production from Equatorial to Sub-Polar Waters
Alexandra T C Broerse

Geomarine Center, Faculty of Earth Sciences, Vrije Universiteit, de Boelelaan 1085, 1081 HV
AMSTERDAM, THE NETHERLANDS. E-mail: bros@geo.vu.nl

The Emiliania Modelling Initiative (GEM) investigates the impact of coccolithophores on
the ocean carbon cycle. In 1994 a project within GEM has been started in order to quantify and map
on a global scale the variety of coccolithophore communities in the recent ocean by month, season
and year and to determine the coccolithophore-CaC03 export fluxes. A few key stations wereselected in a wide range of oceanic settings. I will present a compilation of coccolithophore export
production from stations in the subtropical (34 °N 21 °W) and the temperate Northeast Atlantic(48°N 21 °W), in the Equatorial Pacific (5°S 139°W and l2°S 135°W), in the tropical northwestern
Indian Ocean off Somalia (lOoN 53°E), and in the sub-polar Sea ofOkhotsk (53°N 149°E) in theextreme north-west of the Pacific Ocean, in addition with available data on coccolithophore export
production from literature.
In the equatorial Pacific coccolithophores showed little seasonal fluctuations in fluxes andspecies composition. Mean daily fluxes at 5°S were about 2.1xl08 and at l2°S 2.5xl0 8
coccolithslm21day. The two most abundant species throughout the year were Gladiolithus jlabellatus
and Gephyrocapsa oceanica. The fine fraction (<32 ,urn) CaC03 is used as an estimation for
maximum coccolithophore carbonate fluxes. At 5°S the annual fine fraction CaC0 3 flux was 3.2
g/m21year, presenting only 22% ofthe total CaC03 flux, while at l2°S the fine fraction CaC03
contribution was 68% with 4.2 g/m2lyear.
The production in the tropical station off Somalia in the northwestern Indian Ocean is
influenced by upwelling during the SW monsoon. The average daily coccolith flux was
4.7x10 8lm 21day and the average flux was 3 times higher during the SW monsoon than during theinter-monsoonal period. Florisphaera profunda dominated the assemblage during the start of the
upwelling season, while G. oceanica and Emiliania huxleyi, were dominant in the SW monsoon andthe inter-monsoonal period. The fine fraction CaC03 flux was 7.8 g/m21year, and consisted only 34%of the total CaC03 flux.
In the subtropical Atlantic station the average coccolith flux was highest with
1.1 x 1091m2I day. The spring bloom started in January, and fluxes were about 15 times higher than inother seasons. F. profunda was the dominant species with 50% during pre-bloom conditions, and E.
huxleyi dominated the rest of year between 40-80%. The average fine fraction CaC03 flux was 8.1
g/m21year and contributed 62% to the total CaC03 flux.
In the temperate Atlantic the average daily flux was 3.9xl08 coccoliths/m2/day. The spring
bloom was in April!May with fluxes about 10 times higher than during the rest of the year. E.
huxleyi dominated the coccolith assemblage continuously with 60-80%. The fine fraction CaC0 3
flux was 4.6 g/m21year and contributed only 41% to the total CaC0 3 flux.
In the sub-polar Sea of Okhotsk, which is covered with ice during the winter, the average
flux was 1.6x107 coccoliths/m2/day, with Coccolithus pelagicus dominating during the autumn
bloom in November and E. huxleyi dominating during the beginning of the spring bloom in MarchApril1991, while maximum mass and biogenic silica fluxes were found in June. Besides E. huxleyi
and C. pelagicus no other species were significant. The <32 ,urn CaC03 flux was only 1.5 g/m2/year,
representing 14% ofthe total CaC03 flux.

Coccolithophore (CaC0 3) Fluxes in the Sea of Okhotsk (North Pacific Ocean)Alexandra I. C Broerse
Geomarine Center, Faculty of Earth Sciences, Vrije Universiteit, de Boelelaan 1085, 1081 HV
AMSTERDAM, THE NETHERLANDS. E-mail: bros@geo.vu.nl

Coccolithophore fluxes, and its calcium carbonate contribution were determined in the
Sea ofOkhotsk, a subpolar zone in the extreme north-west ofthe Pacific Ocean. It is, after the
Bering Sea, the largest marginal sea in the world, covered for 80% with first year sea-ice during
an average winter. A sediment trap mooring, deployed in the center of the Sea of Okhotsk at
53°N 150°E (Shoyo station), collected material at 258 m and 1061 m depth from August 1990 toAugust 1991. Two distinct particle blooms in spring and autumn were observed, alternating witha summer and winter slack period. There was an unusually large export production of organiccarbon (mainly in spring) and inorganic carbon (mainly in autumn) to the interior of the Sea of
Okhotsk, with a very extended phytoplankton bloom. The two most dominant coccolithophore
species were Coccolithus pelagicus and Emiliania huxleyi, showing an increase influxes at 258
m depth during both spring and autumn blooms. C. pelagicus was more abundant during theautumn bloom, while E. huxleyi reached maximum fluxes during the spring bloom. Maximum
fluxes of C. pelagicus were reached two weeks after the peak mass flux at 1.6x 106
coccospheres/m2/day in mid- November, and maximum coccolith fluxes in November-December
at 6.6xl07/m2/day, one months after peak mass fluxes. E. huxleyi was most abundant in the
beginning of the spring bloom in March-April1991, while maximum mass and biogenic silica
fluxes were found in June. Peak coccolith and coccosphere fluxes were reached at respectively
3.7xl07 and 1.2xl04/m2/day, respectively. The time weighted mean daily fluxes of all species at
258 m depth were 1.6xl07 coccoliths/m2/day and 2.5xl05 coccospheres/m2/day. The
coccolithophore export production at 1061 m depth was not correlated to that at 258 m.
Due to carbonate dissolution at greater depth E. huxleyi was almost absent and C.
pelagicus showed a decrease in fluxes, while the percentage of corroded specimens increased
dramatically. C. pelagicus showed two peaks at 1061 m, in January-February 1991, and in
April-May 1991, with maximum coccolith and coccosphere fluxes of 1.3x107 and 1.8x105 . Timeweighted mean fluxes at 1061 m were 2.2xl06 coccoliths and 2.1x104 coccospheres/m2/day. To
determine coccolithophore contribution to the total CaC03 flux, the carbonate flux in the fine
fraction (<32 ~m) was measured. Time weighted mean CaC03 fluxes in the fine fraction
decreased from 4.0 mg/m2/day at 258 m to 2.6 mg/m2/day at 1061m, contributing 14 and 10%,respectively to the total carbonate flux. The fine fraction carbonate fluxes included
coccolithophore-CaC03, but also other carbonate sources (biogenic and detrital) were
contributing significantly.

Phytoplankton Dynamics and Environmental Cycles in the Late Jurassic
Kimmeridge Clay - Preliminary Results
Jackie A Burnete, Paul R. Bown 1, Jererny R.Young 2 and Jirn B. Riding 3
1

Dept. of Geological Sciences, University College London, Gower Street, London, WClE 6BT, UK. E-rnail:j.burnett@ucl.ac.uk; p.bown@ucl.ac.uk
2
Palaeontology Dept., The Natural History Museum, Crornwell Road, London, SW7 5BD, UK..
E-rnail: jy@nhrn.ac.uk
3British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.

The preliminary results of our study of virtually mono generic nannofossil assemblages, intandem with dinoflagellate assemblages, from the Kimmeridge Clay Formation (KCF) of
England will be presented. The KCF is an unusual sedimentary package, comprising mostly
mudstones which contain variably preserved nannofossil assemblages, but including three
episodes of concentrated, laminated coccolith sedimentation: the so-called white stone bands.
The nannofloras in the limestone laminations of the white stone bands are extremely
well-preserved, including coccospheres of delicate taxa such as Polypodorhabdus,
Truncatoscaphus and Stradnerlithus, among the almost overwhelming numbers ofWatznaueria
coccospheres. The dark laminations are Corg-rich mudstones and almost devoid of coccoliths,
although imprints ofWatznaueria's can be seen on some bedding surfaces.
The study of the KCF is multilayered, and forms part of a wider project which will
incorporate geochemical and sedimentary analyses and which aims to provide an overall
environmental model of the formation. The virtually mono generic nature of the KCF means thatit has a low biostratigraphic resolution compared to the same interval elsewhere. Relative
abundance and biometric studies of the Watznaueria species has allowed us to improve thissituation, as well as make some comments on the palaeobiogeography of the region, and theseresults will be presented. The enigmatic nature of the light/dark laminations, representing aswitch from coccolith to dinoflagellate dominance in the water-column, is the current focus of
our investigation. The timing of these switches is presently unknown but could represent
seasonal blooms. There is also an indication ofMilankovitch cyclicity in the sequence.

(Cocco)liths versus (cocco)spheres: a method to approachthe ecology and the biostratonomy of Coccolithophores
M Cacbao 1 and A. Oliveira2
1

Dep. Geology Faculty Sciences Univ. Lisbon, Rua Escola Politecnica, n° 58, P-1294
Lisboa Codex, PORTUGAL. E-mail: mcachao@fc.ul.pt
2
JNICT, Univ. Algarve I Portuguese Navy Hidrog. Institute, Rua das Trinas, no 49, P-1200
Lisboa, PORTUGAL

Most of the micropaleontological oriented works performed upon coccolithophorecommunities developing on the upper layers of the water column routinely include the countingof coccospheres (here after referred to as spheres, for simplicity) and heterococcoliths (here after
simply referred as liths) both structures found in the same filters. Subsequently, the coccolithdata is either forgotten or converted to coccospheres by defining, species by species, a certain
and constant number of coccoliths per cell (coccosphere). By doing so a significative (andprobably very important) part of the information may be eliminated not to mention introducing
an additional error source for our data.
In most of the biological research developing upon phytoplankton in general andcoccolithophores in particular an important aspect is to recognize when a particular species isblooming, in a steady developing state or in a decaying process. But how to access this type ofquestions if most ofthe data is gathered along sections in which a station is rarely sampled twice,or at least within a time interval ofthe same order of magnitude ofthe developmental process ofthese microalga ?
Coccolithophores have the particular feature of producing so many complex structures(the liths) which are released by the cells in certain conditions (growing, cell division or grazing
processes). Due to their quite small dimensions (generally between 2 to 15 J.Lm) and their resilient(calcite) nature, liths may persist for a while in the upper layers of the water column. In thesecircumstances, the amount of liths present in the water column, related to the number of cells,
may be considered as an additional source of information. Some sort of"memory" ofthe system.

In the present work we decided to explore this approach. We kept coccolith distinct from
coccosphere data and by means of simple lith versus sphere bivariate graphs and their linear (ornot) correlations to tried to analyse distinct coccolithophore developing or decaying situations.
Our data was gathered offshore from Portugal where, during winters, an Iberian poleward
slope current (the Portuguese Coastal Countercurrent- PCC) develops bringing northwards
subtropical coccolithophore assemblages which normally dwell in waters south of the Azores
Front (Cachao et al., 1998). This data was subsequently used to produce a computer algorithm
which simulates several possible situations.
REFERENCESCACHAO, M., OLIVEIRA, A: & VITORINO, J. (in prep.)- Coccolithophores as oceanographic tracers: a casestudy from the offshore of Portugal.

CODENET- An European Research Network to Study Cocolithophorids
1

M Cacbao ; J. Young 2 ; H. Thierstein 3 ; J. van Hinte 4 ;56
C. Billard ; L. Medlin ; M. Estrada 7 ; and, S. Damste 8
1

2

Museu Nacional de Historia Natural, University of LISBON, PORTUGAL; E-mail: mcachao@fc.ul.pt
Paleontology Department, The Natural History Museum, LONDON, ENGLAND; E-mail: jy@nhm.ac.uk
3
Geological Institute, Swiss Federal Inst. Technology, ZURICH, SWITZERLAND;
E-mail: thierstein@erdw.ethz.ch
4Earth Sciences Faculty, Free University of AMSTERDAM, NETHERLANDS; E-mail: hinj@geo.vu.nl
5
Laboratoire Bioi. Biotechn. Marines, Univ. Caen, BASSE-NORMANDIE, FRANCE;
E-mail: Billard@ibba.unicaen.fr
6
Alfred-Wegener-lnst. Polar & Marine Research, BREMERHAVEN, GERMANY;
E-mail: lmedlin@awi-bremerhaven.de7
Instituto de Ciencias del Mar, Spanish Council for Scientific Research, BARCELONA, SPAIN;
E-mail: marta@icm.csic.es
8
Netherlands Institute for Sea Reseach, NETHERLANDS; E-mail: daamste@nioz.nl

Coccolithophorid Evolutionary Biodiversity and Ecology Network (CODENET) is a
recently created research network, funded by EC TMR program, bringing together eight first rate
geological, marine biological, molecular genetic and organic geochemical research groups fromseven European countries. Multidisciplinarity is essential for investigation of the open ocean
primary production, global carbon, carbonate and sulphur cycles and to interpret global change in
the geological record, with vital importance for marine biologists, biogeochemists andmicropaleontologists.
Coccolithophorids are ideal for such study and since this potential has previously been
exploited via research on the single species Emiliania huxleyi, we believe that to develop it
further a broader taxonomic approach is desirable.
The CODENET research strategy is to take six species spanning the evolutionary
diversity of coccolithophorids. They will be used to: (1) probe high level diversity in key aspectsof its biology; (2) build a representative suite of case studies in species-level diversity andmicroevolutionary processes; (3) study their ecology, quantify their impact on the carbonate
system and study the relationship between coccolithophorid evolution and global change throughthe last 20 Ma. To accomplish these goals a unique combination of experimental study oflaboratory cultures with ecological and evolutionary studies based on plankton, sediment trap,
and geological samples will be carried out.
In what concerns evolutionary diversity the CODENET objectives are: (1) to determine
the major patterns ofbiodiversity in coccolithophorid life-cycles, biomarker composition,
photosynthetic pigments, cytology and plastid genome; (2) to re-evaluate the phylogeny of thecoccolithophorids using separate and combined analyses of molecular, genetic, morphologicaland biochemical data and compare this with the paleontological record of coccolithophorid
evolution; (3) to calculate divergence times of groups and rates of evolution, including molecular
clock calibrations; (4) to reconstruct the sequence of major evolutionary steps incoccolithogenesis, lipid biochemistry, plastid evolution, and life cycle differentiation.

To approach microevolution and species level variation th~ CODENET objectives are:(1) to evaluate which aspects of variation represent genotipic vs. ecophenotipic or ontogenetic
variation; (2) to determine whether intra-specific variability in morphology, physiology andbiochemistry are correlated, defining discrete sub-species; (3) to determine whether physiological .
adaptation occurs within local sub-populations independently of other genotypic characters; (4)to determine whether microevolution occurs by (sub)-species selection or effectively simpatricevolution within ocean-scale populations.
To access coccolithophorid ecology CODENET objectives are: (1) to determine whether
coccolithophorids as a group occupy a distinctive ecological niche, and if so characterise it; (2) to determine which aspects of intra- or inter-specific assemblage variation are most valuable forpalaeoecological calibrations and develop palaeoecological proxies; (3) to determine the extend
to which coccolithophorid carbonate accumulation rate is affected by species composition andevolution.
We hope this comprehensive interdisciplinary study will afford a major breakthrough inunderstanding the evolution and ecology of coccolithophorids and the role they play instructuring biodiversity and processes in the modern ocean and in the past.

Biostratigraphy of Zanclian Deposits in Periadriatic Depression (Western Albania), Basedon Calcareous Nannofossils
L Cohaj I, Xh Islami2 and Sh. Cobaf
1

Oil and Gas Institute, Pier, ALBANIA
2
Alpetrol, Pier, ALBANIAThe Pliocene deposits have a large distribution in Preadriatic Depression. They are
represented by Helmesi and Rrogozhina formations. The first one is dominate by clays with silts
and sandstone intercalations. Rrogozhina formation is composed by massive sandstones andconglomerates. The deposits ofCurrila andKavaja sections (Western Albania) are analyzed inthis study. The abundance, diversity of nannoflora, the presence and/or absence of some index
species such as T. rugosus, C. acutus, D. quinqueramus, etc. permit us to make someconclusions. In terms of Okada and Bukry (1980) the following zones and subzones, A.
tricorniculatus (CNlO), T. rugosus (CNlO/a), C. acutus (CNlO/b) and C. rugosus (CNlO/c) aredetermined. The scarcity of D. quinqueramus in the upper part of the late Miocene makes it
rather difficult to define the Miocene-Pliocene boundary. The representatives of Ceratolithus are
rare, also. The quantity of Discoaster fluctuates with climatic changes. An impoverishment ofassemblages toward the top of the Zanclian deposits is evident. Above all this phenomenon isobserved in Kavaja section where the sandstones and conglomerated are present. In order tomake a correlation between nannofossils and forams the samples have been observed. Both data
have helped to give a fine biostratigraphy.

Calcareous Nannofossil Age-Constrains of Anoxic Pliensbachian Deposits from the Cuenca
Vasco-Cantabrica (Spain)
Maria Jose Comas-Rengifo 1 and Nicola Perme
1
2

Departamento de Paleontologia, Universidad Complutense de MADRID, SPAIN
Dipartimento di Scienze della Terra, PISA, ITALY. E- mail: perilli@dst.unipi.it

This work deals with ammonite and calcareous nannofossil integrated biostratigraphy on
two anoxic Pliensbachian intervals well-exposed in the western sector of the Cuenca VascoCantabrica (northern Spain). The study sections (San Andres, Camino and Tudanca) are locatedin the Santander Province of the Cantabria Community.
The sampled carbonate ramp deposits consist of marlstones, marly limestones andlimestones with intercalation ofblack organic-rich laminated marly and silty claystones. These
deposits provide age-diagnostic ammonite assemblages, that allow us to recognize Jamesoni,
Ibex, Davoei, Stokesi, Margaritatus and Spinatum Zones. The anoxic events, with TOC values
ranging from 1.48 to 11.80, are Carixian (Ibex Zone) and Domerian (Margaritatus Zone) in age.
The calcareous nannofossil biostratigraphy is based on more than 100 closely-spaced
samples, mainly collected from marlstones and marly limestones. Semiquantitative analysis was
performed with a light polarizing microscope. The total abundance of nannofossil assemblages
ranges from rare to few/common and preservation from poor to moderate. The ammonite andcalcareous nannofossil biohorizons identified allow to correlate these organic-rich deposits to thecoeval ones from both Boreal and Tethyan Domains.

Coccolithophore Ecology at the Time-Series Station ALOHA, HawaiiMara Cartes and Hans R. Thierstein
Geological Institute, ETH-Zentrum, CH-8092 ZURICH, SWITZERLAND
E-mails: mara@erdw.ethz.ch; thierstein@erdw.ethz.ch

Cell densities of total coccolithophores and main taxa were determined in 127 samples
from the upper 200m at about monthly intervals between January 1994 and November 1995 at
the time-series station ALOHA, Hawaii. The generally low, but seasonally dynamic
coccolithophore cell density variability is compared with in-situ measurements of environmental
parameters.
A principal components analysis to test for covariance among environmental parameters
separated the data set (limited to the 79 samples with statistically significant cell densities) into
two groups, representing samples from the upper and lower photic zones. Correlation analyses
between cell density variability of the five dominant taxa and potentially controlling
environmental parameters in these separate data sets showed significant improvement ofcorrelation coefficients compared to analyses for the entire photic zone.
In the upper photic zone the cell densities of all dominant taxa are most highly correlatedwith temperature variability (Pearson product-moment correlation r>I0.6I), E. huxleyi and U.
tenuis negatively and U. irregularis and small gephyrocapsids positively. Multiple regression
analyses increased these correlations by about 10% for E. huxleyi with the addition of phospate
and for U. irregularis with the addition oflight (PAR).

F. profunda cell densities are highly negatively correlated with light (r=-0.76) andpositively correlated with nitrates (r=0.65), which corresponds to the maximum bottom-up
control (i.e. by physical forcing) of any species encountered.
The surprisingly low correlations of cell densities with nitrate and phosphate may becaused by insufficient sampling resolution, nutrient levels close to detection limits, or both.
A comparison of the optima of all encountered taxa indicates that they occupy themultivariate environmental space continuously but in a consistent sequence.

Variety of Exothecal Coccoliths of Syracosphaera
Llursa ems

Institut de Ci(mcies del Mar (CSIC), Passeig Joan de Borb6 s/n, 08039 BARCELONA, SPAIN.
E-mail: Iluisa@icm.csic.es. The characteristic coccoliths of the genus Syracosphaera are the caneoliths; they
constitute the mono thecate coccolith cases and the endotheca of the dithecate coccospheres ofthis genus (Jordan et al. 1995). Frequently these coccoliths show little differences between
species, sometimes it is even difficult to distinguish them clearly. However, the exothecal
coccoliths present a high morphological variety and has different patterns of distribution on theendotheca; even the name "deviating coccoliths" (Heimdal & Gaarder, 1981; Jordan et al., 1995)
is applie to one kind of coccolith distribution only, around the apical pole. Furthermore thefrequency of exothecal coccoliths is variable. In some species they rarely occur and sometimes
never. This study shows for the first time eight instances of exothecal coccoliths not recognized
before; some of them are cyrtoliths, but some are clearly caneoliths (for terminology see Braarud
et al. 1955; Heimdal, 1993 and Jordan et al. 1995). Moreover, a tentative classification of theexothecal coccoliths of the Syracosphaera species found in the NW Mediterranean is presented.
Those different exothecal coccolith morphologies and distributions may be related to thephylogenetic proximity between the Syracosphaera species.

REFERENCES:
BRAARUD T DEFLANDRE, G., HALLDAL, P., AND KAMPTNER, E. 1955. Terminology, nomenclature, ands~st~matics of the Coccolithophoridae. Micropaleontology, 1 (2): 157-l59: d

HEIMDAL, B. R. 1993. Modem Coccolithophorids. ln: Marine phyt~pl~on. AdGm e to

Naked Flagellates andT
A d mic Press Lmnted. Lon on.
.
Coccolithophorids. Ed. by C.R. omas. ~a e h .ds fr
the northern part of the eastern central AtlantJ.c.
HElMDAL, B. R. ANDGAARDER, K :R- :.98 1. c~~cohthop on .
Reihe D, 33: 37-69.
II. Heterococcolithophonds. Meteor Forsch.-Ergebms\, A lossary of the extant haptophyta of the
JORDAN, R.W., KLElJNE, A., HEIMDAL, B.R AND GREEN, J.C. 199 .
gworld. J. mar. biol. Ass. U.K. 75: 769-814.

o:~-----

New Examples of Holococcolith-Heterococcolith Combination Cells and Their
Implications for Coccolithophorid PhylogenyLlu)sa Cros 1, Annelies Kleijne 2 , and Jeremy R. Young3
1

Institut de Ciencies del Mar (CSIC), Passeig Joan de Borb6 s/n., 08039 BARCELONA, SPAIN.
Email: lluisa@icm.csic.es
2
Earth Sciences, Amsterdam Free University, 1081HV AMSTERDAM, THE NETHERLANDS.
3
Palaeontology Dept., The Natural History Museum, LONDON SW7 5BD, UK. E-mail: jy@nhm.ac.uk

Combination cells can provide invaluable clues to life cycle transitions within coccolithophorids.
As described by Thomsen et al. (1991), these are cells with composite coccospheres including two partial
layers of coccoliths which normally occur on separate coccospheres. Three new examples ofcombination cells bearing both heterococcoliths and holococcoliths have recently been observed during
study of samples from the NW Mediterranean and are presented here for the first time. The cells
comprise: Syracosphaera anthos (Lohmann) Janin with Periphyllophora mirabilis (Schiller) Kamptner,
Helicosphaera carteri (Wallich) Kamptner with Syracolithus catilliferus (Kamptner) Deflandre andSyracosphaera sp. type K Kleijne (1993) with Corisphaera sp. type A Kleijne (1991). Two further
combination cell types previously reported have been observed again: Coronosphaera mediterranea with
Calyptrolithina wettsteinii, found previously by Kamptner (1941); and Syracosphaera sp. type A withheterococcoliths and holococcoliths, found previously by Kleijne (1991). Helicosphaera carteri, which
has been selected as a key species in the CODENET network, and Syracolithus catilliferus are
sufficiently abundant in the NW Mediterranean samples, to have reliable data on their distribution in thewater column.
Usually these monomorphic species eo-occurred at the same stations, with S. catilliferus closer
to the surface (0-20 m.) and H. carteri below 30 m. depth. It is likely that the holo-heterococcolith
combination cells represent a transition between two different stages in the same life-cycle and so thedifferent distributions in the water column of the involved "species" are likely to be an expression of theecological strategy of the some coccolithophorids. In addition the association recently presented by
Alcober and Jordan (1997) involving the heterococcolithophorid, Neosphaera coccolithomorpha
Lecal-Schlauder with the nannolith bearing species Ceratolithus cristatus Kamptner, was found. There
was no obvious ecological separation between these species, they usually eo-occurred in the same
stations but both in the surface water samples. Previously holo-heterococcolith combination cells were
only well documented from the Coccolithaceae and Papposphaeraceae. Our results confirm previous
tentative observations of combination cells in the Syracosphaeraceae and for the first time document
them in the Helicosphaeraceae (order Zygodiscales). As a result it now becomes reasonable to predictthat this is a widespread pattern in coccolithophorids, with heterococcoliths occurring on diploid phases
and holococcoliths on haploid phases (see also Billard, 1994; Young and Bown, 1997). The modern
nannoflora include about 50 holococco1ithophorid species and 40 species of Zygodiscales andSyracosphaera1es, simple life-cycle pairing of these species is a likely outcome of future research.

REFERENCESALCOBER, J. AND JORDAN, R.W. 1997. An interesting association between Neosphaera coccolithomorpha andCeratolithus cristatus (Haptophyta). European Journal ofPhycology 32: 91-93. Billard, C. 1994. Life cycles. In :Green J.C. & Leadbeater B.S.C. (eds.), The Haptophyte Algae. Systematics Association Special Volume, 51 ,Oxford University Press, 167-186.
KAMPTNER, E. 1941. Die Coccolithineen der Siidwestkiiste von Istrien. Naturh. Mus. Wien, Ann. Anz., 51: 54-149.
Kleijne, A. 1991. Holococcolithophorids from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic
Ocean. Marine Micropaleontology 17 (1/2): 1-76.
KLEIJNE, A. 1993. Morphology, taxonomy and distribution of extant coccolithophorids (calcareous nannoplankton).
FEBO, Enschede, The Netherlands, Vrije University, Amsterdam, 321 p., PhD thesis.
THOMSEN, H. A., 0STERGAARD, J. B., AND HANSEN, L. E. 1991. Heteromorphic life histories in arctic coccolithophorids(Prymnesiophyceae). Journal ofPhycology, 27: 634-642.
YOUNG J. R. & BoWN P .R. 1997. Proposals for a revised classification system for calcareous nannoplankton. Journal of
Nannoplankton Research, 19 (1): 15-20.

Calcareous Nannoplankton Dominance Shifts of the Plio-Pleistocene:
Global Significance and Implications for Biostratigraphy
Richard A Denne
Applied Biostratigraphix, 2 Treescape Circle, The Woodlands, TEXAS, USA 77381.
E-mail: RicbDenne@aol.com

Due to the relatively low number of genera and species of calcareous nannoplankton,
extinction theorists have generally relegated their Plio-Pleistocene extinction patterns to being
merely "background extinctions". Quantitative examination of material from the Gulf of Mexico
and Caribbean areas, however, indicates that a series of rapid assemblage turnovers during the
Plio-Pleistocene caused the dominant Miocene genera (comprising up to 95% of the nannoflora)
to become either extinct or extremely rare. It was also found that the dominant genera of the
Pleistocene (comprising up to 99% ofthe nannoflora) evolved during the Plio-Pleistocene.
Six genera dominated the upper Miocene calcareous nannoplankton assemblage.
Reticulofenestra was found to be the most dominant genus from the lower Miocene until theupper Pliocene, comprising from 40 - 80% of the nannoplankton assemblage. Other common
upper Miocene genera include Dictyococcites (up to 40%), Sphenolithus (up to 15%), Discoaster(up to 10%), Helicosphaera, and Calcidiscus (both under 5%).
The Pliocene is characterized by a series of generic abundance changes, as opposed to thestability of the upper Miocene. Sphenolithus dropped precipitously in abundance during thelower Pliocene (NN14), and became extinct by the upper Pliocene (NN16). Discoaster, a genus
common throughout most of the Tertiary decreased in abundance during the upper Miocene(NNll) and again in the upper Pliocene (NN16), and was extinct by the end of the Pliocene(NN18). Reticulofenestra nearly doubled in abundance above the Plio-Miocene boundary(NN12), and remained abundant throughout most of the Pliocene. However, near the top of the
Pliocene (NN16) the genus nearly went extinct, being reduced to very rare occurrences in the
Pleistocene. This is also true for Dictyococcites, which became very rare after the middle
Pliocene (NN15).
Four genera were found to be dominant during the Pleistocene. Both Pseudoemiliania
and Gephyrocapsa evolved during the middle Pliocene (NN15) and rapidly became common.
During the lower Pleistocene (NN19) Pseudoemiliania comprised up to 35% of the calcareous
nannoflora assemblage, but dropped rapidly in abundance in the middle ofthis zone and was
extinct by its end. Gephyrocapsa became the dominant genus (40- 99%) during the upper
Pliocene (NN16), and remained so until the uppermost Pleistocene (NN21), when the recently
evolved genus Emiliania became dominant (up to 80% ofthe assemblage). Helicosphaera
comprised approximately 5% of the assemblage during the lower Pleistocene, but dropped toonly 1% by the middle Pleistocene.
As many of the Plio-Pleistocene dominance shifts occurred over a very short period oftime, they represent extremely useful biostratigraphic horizons. When taken to the species level,as many as 16 abundance shifts are found within the dominant genera ofthe Plio-Pleistocene, asignificant increase over the nine horizons derived from first and last occurrences.

Biosteering on 'Mars'- Reducing Uncertainties of Horizontal Drilling
Alvin DuVemay
Mississippi Canyon Block 807 #A-1 ST, Gulf of Mexico - USA
E-mail: alduv@shellus.com.

Biosteering is a geosteering tool for adjusting well track orientation while horizontal
drilling. It reduces uncertainties of other enabling technologies by utilizing real-timebiostratigraphic interpretation. Discrimination of specific sands and shales is achieved by thecontinuous analyses of ditch cuttings.
Biosteering is a proven technology by Shell and other international Companies but israrely utilized by Gulf of Mexico operators. Deposition rates are perceived to be too rapid for thedevelopment of unique reproducible paleontologic signals within reservoir seal pairs. Successful
biosteering of the Pink sand horizontal well (MC 807 #A-1 ST, Shell USA GOM) at Shell's Mars
Field was facilitated by creating and rigorously implementing a feasibility study. Ample leadtime, high resolution biostratigraphy on multiple control wells and a robust sampling program of
conventional core through the reservoir and bounding shales were key success factors to thisstudy.
The Mars Pink interval (including bounding shales) was deposited in approximately
600,000 yrs. The Pink sand is interpreted to be a lowstand depositional event between the NPM 4
maximum flooding surface (LAD D.challengeri, E. Zanclian) and the NPM 4.3 lowstand system
tract (LAD D.bergrennii, L. Messinian). Real-time determination of the bottom hole assembly
position was established by on-site nannofossil sample exam and interpretation of these system
tract fossil assemblages.

The Virtual Paleontologist,or:Children as Real Paleontologists
Yoram Esbet
Geological Survey oflsrael, 30 Malkhei Israel St., JERUSALEM, 95501, ISRAEL
E-mail: yoram@mail.gsi.gov.il

Paleontology can be best described as a discipline of science, in which fossil evidence iscollected, identified, analyzed, and interpreted in order to build models that reconstruct the world
as it was in ancient times. We know from our work how complex this process, of data collection,
analysis and reconstruction can be. But, could you believe that a small elementary-school kid canfill the boots of a paleontologist, and come up with high-level reconstructions of the ancientworld, that are not much different than yours - the "big" paleontologist? Well, if you still doubt
it, Message In A Fossil may just convince you. Message in A Fossil is an educational multimedia
simulation for elementary-school students, that was developed under the author's scientificsupervision. The aim of the program is to allow students to play the "real"role of a paleontologist
and experience the methods of data collection, analysis, and synthesis that scientists use inscientific investigations. In the program, the students dig in a virtual paleontological excavationand discover fossils. They use an on-line fossil reference collection to identify and interpret theirfinds. The students even put together broken fossils and reconstruct complete skeletons.
At the end of their investigation, the students build a museum-diorama of the ancient
habitat that matches the evidence they found. Many schools in the United States are currently
using this program as part of their earth science and life science curriculum. It is currently usedby schools in Texas as part of an innovative curriculum or as a component of athematically-based curriculum.

Paleocene Calcareous Nannofossil Biostratigraphy in Israel- Preliminary Results
Yoram Eshet and S. Moshkovitz
Geological Survey oflsrael, 30 Malkhei Israel St., JERUSALEM, 95501, ISRAEL
E-mail: yoram@mail.gsi.gov .il

The Paleocene sequence of Israel is composed of about 70 meters of marls and chalks thatwere deposited in hemipelagic environments. The calcareous nannofossils biostratigraphy of thesesequences is investigated as part of a multidisciplinary correlation study of the Paleocene in Israel.
The present paper includes the preliminary calcareous nannofossil zonation and correlation for theMaastrichtian to Early Eocene. Except for minor modifications, the nannofossil zonation scheme ofMartini (1971) was found applicable in the Israeli sections. The following nannofossil zonation
was defmed: 1. Micula prinsii Zone (latest Cretaceous): The interval from the First Occurrence(FO) of M prinsii to the FO of abundant acme of small Biscutum spp. 2. Markalius inversus Zone
- NPl (Early Paleocene): The lower zonal boundary is placed according to the first bloom of anassemblage dominated by small Biscutum species, as B. romeinii and B. parvulum, that form anacme slightly above the K-T boundary, and are considered to be the earliest Paleocene markers(Perch-Nielsen, 1985). The FO of the Paleocene Cruciplacolithus primus occurs slightly above the
Biscutum acme. The top of the zone is determined by the FO of Cruciplacolithus tenuis.
Cretaceous forms continue to be prominent in this zone, a phenomenon which is well known frommost K-T boundary sections worldwide. 3. Cruciplacolithus tenuis Zone- NP2 (Early Paleocene):
From the FO of C. tenuis to the FO of Cruciplacolithus danicus. 4. Cruciplacolithus danicus Zone
- NP 3 (Early Paleocene): from the FO of C. danicus to the FO of Ellipsolithus macellus. 5.
Ellipsolithus macellus Zone- NP 4 (Early Paleocene): From the FO of E. macellus to the FO of
Fasciculithus tympaniformis. Cretaceous forms disappear almost completely from this zone andupwards. 6. Fasciculithus tympaniformis Zone- NP 5 (Late Paleocene): From the FO of F.
tympaniformis to the FO of Heliolithus kleinpelli. The first occurrence of the genus Discoasteroccurs at the top of this zone, with the FO of a multi-rayed taxon, tentatively named here
Discoaster sp. A, which has about 40 rays. 7. Heliolithus kleinpellii Zone- NP 6 (Late Paleocene):
From the FO of H. kleinpellii to the FO of Discoaster mohleri. 8. Discoaster mohleri Zone - NP 7
(Late Paleocene): From the FO of D. mohleri to the FO of Heliolithus riedelii. Since H. riedelii ismissing in the studied sections, NP 7 and NP 8 were combined into a NP 7-8 Zone, from the FO of
D. mohleri to the FO of D. multiradiatus. 9. Heliolithus riedelii Zone- NP 8 (Late Paleocene):
From the FO of H. riedelii to the FO of Discoaster multiradiatus. Because H. riedelii is missing in
the present study we combined NP 7 and NP 8 into a NP7-8 interval, as done by most authors who
faced the same problem. 10. Discoaster multiradiatus Zone- NP 9 (Late Paleocene): From the FO
of D. multiradiatus to the FO of Tribrachiatus bramlettei. In the transition from NP 7-8 to NP 9,
Discoasters reduce the number of rays from about 40 (Discoaster type A) to about 18-30 rays.
This change marks a world-wide ray-reduction trend (Moshkovitz, 1967; Romein, 1979; Wei andWise, 1989) that continues well into the Early Eocene. 11. Tribrachiatus contortus Zone - NP 10(latest Paleocene-Early Eocene): From the FO of Tribrachiatus bramlettei to the LO of
Tribrachiatus contortus. The Paleocene-Eocene boundary is drawn within the lower part ofNP 10,
at the top of the planktic foraminifera Morozovella velascoensis Zone (P6a). The FO ofT.
contortus is found close to the top ofNP 10. In some of the sections, the LO ofT contortus could
not be defmed with certainty, and the FO of Tribrachiatus orthostylus Type B was used to markthe top of the zone, following Perch-Nielsen, 1985). T orthostylus Type A first appears slightly
below the FO ofT orthostylus Type B, within NP 10. 12. Tribrachiatus binodosus Zone- NP 11(Early Eocene): From the LO ofT contortus to the FO of Discoaster lodoensis. In the present
study, the FO ofT. orthostylus Type B was found useful to determine the base of the zone.

Palaeoceanological Reconstruction of the Late Quaternary Agulhas Current (South
Atlantic) Based on Calcareous and Organic Walled Dinoflagellate Cysts
Oliver Esper, Karin Zonneveld and Hehnut Willems
Fachbereich 5 - Geowissenschaften, Universitat Bremen, Postfach 33 04 40, 28334 BREMEN, GERMANY
E-mails: esper@zfn.uni-bremen.de; willems@micropal.uni-bremen.deIn the last decades it has become apparent that climatic change is greatly influenced bychanges in the global ocean current systems. One of the most important systems is the thermohaline
circulation of the Atlantic Ocean, which transports cold, higher saline water from the northern
Atlantic to the southern hemisphere and in return transports warmer water of the South Atlantic to
the north, positively influencing the northern continental climate. To understand the fluctuations in
the heat flux through glacial/interglacial changes in the Late Quaternary, it is necessary to study
several key areas. One of such areas is the eastern South Atlantic, where warmer Indian Ocean wateris carried around the cape of South Africa through the Agulhas Current into the Atlantic Ocean. The
aim of the present study is to reconstruct the palaeoceanology of this region.
Changes in ocean currents can be detected through the analysis of different constituents ofthe seafloor sediments. One useful tool are dinoflagellate cysts. These micro-organisms possess alife cycle with a planktonic thecate stage, sensitive to environmental parameters like watertemperature, salinity, and nutrient supply, and a corresponding resting cyst stage. Depending on thespecies, there are two different groups offossilisable dinoflagellate cysts (dinocysts) distinguishable
through the nature of their wall material: organic walled and calcareous dinocysts.
In this study, an approach is made to correlate and compare results of the analysis of organic
walled dinocyst assemblages with calcareous walled dinocyst assemblages and the calcareous
vegetative stage of Thoracosphaera heimii. Samples are taken from sediments of core GeoB 3603-2
located in the southern Cape Basin offshore South Africa, and cover the time interval from oxygenisotope stage 6 (150.000y BP) to the Recent, thereby including the last three deglaciations. The
results are used to reconstruct the palaeoenvironment and palaeoceanography of the Agulhas Current
during glacial and interglacial times in order to gain more knowledge on the role of the thermohaline
circulation on global climatic change.

Trade-Wind Effect in the Sea Surface dynamic OffWest-Africa (5°N)
During the Last Climatic Cycle
J A Flores, M.A. Barcena, and J.F. Sierro
Dpto. Geologia. Fac. Ciencias. Universidad de Salamanca. 37008- SALAMANCA, SPAIN
E-mail: flores@rs6000.usal.es

The Camel-1 gravity core was recovered during the CAMEL-93 BIO Hesperides cruise(Mid-oceanic Equatorial Canyon-93) in Sierra Leone Rise (Equatorial Atlantic) at
5°6'25S/21 °2'36W. Water depth at the core location is 2686 m. The total length ofCamel-1 is446 cm. The stratigraphic control, based on the 5 180 record of the planktic foraminifer
Globigerinoides ruber, as well as with the CaC03 content and weight percentage of thoseforaminifers < 63 ,urn, allowed the identification of isotopic stages (IS) 6 to 1, in the uppermost
160 cm ofthe core. Additional stratigraphic control data were obtained from the nannofossil
record. Two reversals between E. huxleyi and medium sized Gephyrocapsa (MG) were observed
at 83 and 40 cm core depth, and dated at 80,000 and 40,000 years respectively.
Freshwater diatoms (Aulacosira sp.) in eolian sediments come from erosion of
diatomaceous deposits in dry lake beds, while opal phytoliths are injected into the atmosphere by
fires and wind storms during dry seasons. IS's 6, 5.4/5.3, 4 and 2 have been interpreted as arid
periods, with desiccation of lakes and a migration of the grass belt bordering the western Sahara.
The maximum in opal phytoliths at the IS 3 has been interpreted as an intense humid period, withhigher grass-brush biomass which develops during the raining seasons.
At the core location of Camel-1, surface waters are mesotrophic. Under this conditions,coccolithophorids are the most important primary producers. The dominant taxa is F. profunda(75 to 95 %). This coccolithophorid is related with a deep nutricline and therefore with low
nutrient concentration at the surface. During IS 6, 5.4, 5.2, 4 and 2, minimum values of F.
profunda were recorded and related with a shallower nutricline position. If during glacial
episodes, the a trade-winds were intensified, it were insufficient to break at all the water column
stability.
Other taxa, such as MG, Helicosphaera spp., Syracosphaera spp., C. leptoporus show asimilar trend than the 18 0 curve.

oFunding for this work was supported by the CICYT projects ANT931 008 C0203, ANT940277 and the DIGICYES
project PB95-0927-C02-0 1.

Sea Surface Dynamics and Paleomonsoon Variability in the South China Sea
for the last 140,000 years
Iose-Abel Flares 1 , F. Javier Sierra 1, Caries Pelejero2, Joan Grimalf,
Luejiang Wang 3 and Michael Sarnthein3
1

Universidad de SALAMANCA. SPAIN. Email: flores@rs6000.usal.es
2
CSIC. BARCELONA. CATALONIA. SPAIN.
3
University ofKIEL. GERMANY

The South China Sea (SCS) is a marginal sea with a climate and hydrography mainly
affected by monsoon activity and sea level changes. Here we report Coccolithophores andmolecular records from core 17961-2 (8°30.4' NI 112°19.9'E, 1968 m depth) obtained during the
RN SONNE cruise in April-June 1994 (Sarnthein et al., 1994).
Core 17961-2 is located on a plateau in front of the Sunda shelf, an area affected during
glacial periods by fluvial sediment discharge of the Molengraaff!Paleo-Sunda River. This riverentered the SCS north of Western Borneo. A detailed study based on molecular biomarkers was
already presented by Pelejero et. al (1996).
Combined 0 180 data from the planktic foraminifera Globigerinoides ruber and AMS
radiocarbon ages provide a precise age control. Regardi.D.g the coccolithophore record, the bottomof the Emiliania huxleyi acme is placed at about 85 ky B.P. An increase in the relative abundanceof E. huxleyi is observed near 30 ky B.P. Below 100 ky a drastic increase in the Gephyrocapsa <3.um is observed. The interval between 40 and 7 ky B.P. is characterized by an increase in theabundance of Emiliania > 4.5 .urn. The near-bottom section of the core is compacted by the coretechnique with the consequent reduction in the sedimentation rate.
Sea Surface Temperature (SST) values were obtained using the relative composition of
di- and triunsaturated C37 alkenones, the U\ 7 index, and the calibration recently established for
the South China Sea (Pelejero and Grimalt, 1997). For comparison, we also plottedSST obtainedwith the commonly used calibration derived by Prahl and Wakeham, 1987, which only leads
minor differences (0.2°C at the most). The SST profiles follow a typical glacial-to-interglacial
pattern, with a 2.5°C difference between today and the Last Glacial Maximum (LGM). Thisdifference is larger than that reported for the low-latitude open Pacific, showing a different
record ofthis marginal sea with respect to the open ocean at the same latitudes. The SST
estimates for stage 5e are relatively high (28.8°C) as compared to modem temperature estimatesof27.7°C, which approximately match the actual annually averaged SST value measured in thisregion. Hence we infer a 1.1 °C warming of stage 5e versus Holocene. The warmer episodes,
when dilution by fluvial mud has been low, are characterized by high concentrations of (total)
coccolithophores and good preservation. This is especially significant during stages 1 and 3.
Stages Se and Se show less significant peaks. Minimum values of coccolithophores are observed
during stages 2 and 4. The general trend of% CaC03 parallels the coccolithophore
concentrations.
Florisphaera profunda show a reduction in their proportion during stages 2, between
stages Sa and Sb, and during Sd. Differences in SST between IS 1, 3, 4 and 5 suggests that the F.

profunda dynamics are mainly linked to the nutricline stability rather than to other factors. Thisis most evident comparing the lower photic layer inhabitants with the upper and medium photic
layer inhabitants (excluding in both groups those species that are not exclusive of one of thelayers). According with these data, stages 2, 4, 5b and Se were characterized by a shallower
nutricline, with a higher vertical mixing in the water column.
Samthein et al (1996) ascribed the 6 18 0 minima at 300 and 450 cm to low-salinity events
for time periods corresponding close the Heinrich events H3 and H4. A further important peakoccurs near 40 ky These low salinity events are linked to maxima in Syracosphaera spp. D.
tubifera and G. oceanica. Other species, such as N coccolithomorpha, seem to show an opposite
pattern.
Concentrations (ng/g) ofterrestrially derived nonacosane and hexacosan-1-ol are alsopresented. These profiles show a high sensitivity of the South China Sea to the influence ofcontinental waters, tracing the probable inundation of the Sunda Shelf around 12-13 cal kyr B.P.
This catastrophic event parallels an abrupt increase in F. profunda abundances, probably
reflecting a change from shallow to deep nutricline, and/or an increase in turbidity.
REFERENCES:PELEJERO C., GRIMALT, J.O., SARNTHEIN, M. AND WANG, L. (1996 variations in Uk37 sea surface temperature andmarine/terrestrial biomarkers in the South China Sea during the last 130.000 years. - 30th Intemat. Geol.
Congress, Beijing, China, 4- 14 August, 1996, Abstracts.
PELEJERO C. AND GRIMALT, J.O., 1997. The correlation between the Uk37 index and sea surface temperatures in thewarm boundary: The South China Sea. Geochim. Cosmochim. Acta, 61:4789-4797.
PRAHL F.G. AND WAKEHAM S.G., 1987. Calibration ofunsaturation patterns in long-chain ketone composition for
paleotemperature assessment. Nature, 330: 367-369.
SARNTHEIN, M., PFLAUMANN, U., WANG, P.X. AND H.K. WONG (1994): Preliminary Report on Sonne-95 Cruise"Monitor Monsoon" to the South China Sea.- Reports, Geol.-PaHiont. Inst. Univ. Kiel, Nr. 68, 225 p.
SARNTHEIN, M., L. WANG, S. HEILIG, et al. ( 1996): Response of East Asian monsoonal climate to orbital forcing andfluctuations of the ocean salinity conveyor belt: High resolution sediment records from the South China
Sea.- 30th Intemat. Geol. Congress, Beijing, China, 4- 14 August, 1996, Abstracts.

Biostratigraphic and Paleoceanographic Significance of the Late Middle Miocene - Early
Pliocene Calcareous Nannofossils from the Coast of the Sea of Japan, Northeast Japan
Kazue Fukasawa 1 and Chilcara Hiramatsu2
JAPEX Research Center, 1-2- 1, Hamada, Mihama-ku, Chiba, JAPAN, 261
E-mail: kazue@rc.japex.co.jp Phone:+81-43-275-9311Fax:+81-43-275-9316

The Sea of Japan located between the Asian Continent and Japanese Islands, is thought to haveappeared during late Oligocene to early Miocene, and has developed as a back-arc basin of Japan.
From late Middle Miocene to early Pliocene, the calcareous microfossils are extremely rare in the
coast of the Sea of Japan because of it's own characteristic environment ; stagnant and quiet waters.
Therefore, it is difficult to apply the standard Neogene nannofossil zones (Okada and Bukry, 1980) tothat region.
In order to contribute to the further understanding of the Neogene calcareous nannofossil
occurrence, marine sediments in the coast of the Sea of Japan were examined in detail. Four types ofcalcareous nannofossil assemblages were recognized. Supplementary biostratigraphic analyses ofplanktonic foraminifers, diatoms and radiolarians have been carried out. The integrated
biostratigraphic studies allowed us to recognize, at least, the four calcareous nannofossil occurrence
intervals which are correlative with CN5a-b, CN8, CN9 and CNl0-11, respectively.
The marker species of CN9, Discoaster quinqueramus regarded as a warm water indicator,
was recognized from Yamagata to Hokkaido(Okada, 1988). Discoaster species was also found for theCN8 and CN5a-b intervals as well. Moreover, tropical and warm water planktonic foraminifers wereidentified in the same samples assigned to the CN5a-b(Inoue, 1995) and CNl0-11 intervals.
The planktonic foraminiferal fauna from the late Middle Miocene to early Pliocene in the coastof the Sea of Japan consists of cold water species in general(Matoba, 1984). But the above results
suggest the intermittent warm water inflows to that region.
According to Barron and Baldauf (1990), the time intervals of CN5b-6 and CN8-9 werecorrelated with their Climatic Optima 2 and 3, respectively. Therefore, CN5a-b, CN8 and CN9intervals in the Sea of Japan indicate that the inflows are possibly related to the global climaticchanges. Additionally, the results are useful to the correlation of the late Middle Miocene to early
Pliocene marine sediments of the coast of the Sea of Japan, in which correlative markers were few.
Further analyses of calcareous nannofossil in the region will become applicable data for moredetailed correlation and reconstruction ofpaleoceanographic changes.

REFERENCES
Barron, J. A . and Baldauf, J. G., 1990: Development ofbiosiliceous sedimentation in the North Pacific during the
Miocene and Early Pliocene. In Tsuchi, R. (Ed.), Pacific Neogene Events, University of Tokyo
Press, p . 43-63.
Inoue, Y., 1995: Warm planktonic foraminifera from the Middle to Late Miocene formations in the oil fields ofnortheast Japan. Abstr.,The Technical Meeting of the Jap. Assoc. Petro. Tech.,l995, p.64 (in Japanese).
Matoba, Y., 1984: Paleoenvironment of the Sea of Japan. In Oertli, H. J. (Ed.), Benthos'83, 2nd Int. Symp. Benthic
Foraminifera, p. 409-414.
Okada,H. and Bukry,D., 1980: Supplementary modification and introduction of code numbers to the low - latitude
coccolith biostratigraphic zonation (Bukry, 1973; 1975). Mar. Micropal., v. 5, p. 321-325.
Okada, H., 1988: Neogene calcareous nannofossil stratigraphy of northern part in the northeast Japan. In Iijima, A.
(Ed.), Synthetic Study of Tertiary Siliceous Shale Formation, University of Tokyo Press, p.81-86 (inJapanese).

Coccolith biometrics: A High Resolution Case Study in the Hauterivian (early Cretaceous)and Planned Work in the CODENET Project
Marlcus Geisen, 1 Jorg Mutterlose, 1 and Jeremy R. Young 2
1

Institut fur Geologie, Rubr-Universitat Bochum, Universitatsstrasse 150, Bochum, FRG.
E-mail: marcus.geisen@ruhr-uni-bochum.de
2
The Natural History Museum, Cromwell Road, London, GB. E-mail: jy@nhm.ac.uk

Coccolith morphology and morphological variation in the fossil record may provide signalsof both evolutionary change and ecological control. Within the CODENET (Coccolithophorid
Evolutionary Biodiversity and Ecology Network) the nature and interaction of these effects will be
investigated for selected genera. A series of constrained case studies will include: (1) Study ofculture populations from different strains of single species in combination with molecular genetic
and physiological data on other aspects of variation; (2) study of culture samples from single strains
grown under varying ecological conditions; (3) study ofwater column samples; (4) study ofbroad
geological time series and (5) study ofhigh resolution geological sample sets with well constrained
independent evidence of ecological variation. In all cases morphological variation will be studied
using image analysis based on morphometric techniques. This poster outlines the basic methodology
to be employed and illustrates a directly comparable case study recently undertaken by the firstauthor.
In order to investigate the intensity of ecological control on the morphology of Watznaueria
coccoliths a high resolution study was carried out. The material is derived from a section in NW
Germany (Frielingen clay-pit, NW Hannover), which exposes clay-marl bedding rhythms on thescale ofMilankovitch cycles (Mutterlose & Ruffelll997). 27 samples from a 2.7 m thick sequence,
consisting of four clay-marl bedding rhythms, were examined. 60 coccoliths in each sample havebeen analyzed biometrically, using a light microscope and digital image capture techniques, in orderto gain size and shape parameters. The following sediment geochemical data were also considered :CaC0 3, Corg• total carbon and sediment color.

Results
Despite the strong micropalaeontological, litho logical and geochemical signals of ecologicalchanges throughout the section, there is remarkably little variation in coccolith size and shape.
Virtually all assemblages have mean coccolith lengths within the range of 5.5-6.2 microns. Thissuggests that the size distribution of Watznaueria is not strongly influenced by ecology, which
reinforces the value of study oflong term, evolutionary variability. Nonetheless when examined indetail some consistent morphological variation is detectable in the data set:
• In pale beds the range of measured lengths is greater than in dark beds.
• Pale beds show a dominance of coccoliths with a large outer shield.
• Compared to the dark beds pale beds show a dominance of mature (sensu Young & Bown 1991)
and relatively large coccoliths.
These results seem to represent autecologica1 variations in coccolith size and shape distribution, witha strong influence of variable ontogenetic development, and they appear to correlate with thesediment geochemical data.
Literature
Mutterlose, J. & Ruffell, A. (1997): Frielingen clay-pit.- in: Mutterlose, J., Wippich, M. G. E. & Geisen, M. [Eds.]:
Cretaceous Depositional Environments ofNW Germany, Bochumer geologische und geotechnische Arbeiten, 46 :105-121.

Young, J. R. & Bown, P. R. (1991): An Ontogenetic Sequence ofCoccoliths from the Late Jurassic Kimmeridge Clay of
England.- Palaeontology, 34 (4): 843-850.

Comparison oftheWatznaueria Genus Signal Recorded in Tethyan and Boreal Areas
During the Middle and Upper Jurassic
F Giraud 1, E. Mattioli2 , B. Pittef, F. Atrops 1 and B. Courtinat 1
1

Universite Lyon I, Centre des Sciences de la Terre, UMR 5565, 27-43 boulevard du 11 novembre, 69622

VILLEURBANNE CEDEX, FRANCE
2

Universita degli Studi di Perugia, Dipartimento di Scienze della Terra, Piazza Universita, 06100 PERUGIA,
ITALY
3
Universite de Fribourg, Institut de geologie et paleontologie, Perolles, CH-1700 FRIBOURG, SWITZERLAND

The Family of the Watznaueriaceae represents one of the most important planktonic
carbonate producer in the Middle-Upper Jurassic sediments. The dominance of this Family overother coccoliths began at the Aalenian!Bajocian boundary, when Watznaueriaceae experienced asignificant evolutive radiation. The Watznaueriaceae substituted at this stage the calcareous
dinoflagellate cyst Schizosphaerella spp. as carbonate producer, while the abundance of
Schizosphaerella spp sensibly decreased. This speciation is probably related to a crisis in the
coccolithophorid community, as species diversity is overall low and the assemblages areworldwide dominated by the genus Watznaueria . As it is observed in Middle to Late Jurassic
sections presenting variable lithotypes and located in different palaeogeographical domains, thedominance of Watznaueria spp. seems not to be a consequence of a selective diagenesis.
The Middle-Upper Jurassic limestone-marl alternations from several localities in southeastern France, central Italy and southern Germany, are selected for study the space and time
distribution of different species of the genus Watznaueria. The south-eastern France sections areon the Ardeche margin and in the Dauphine basin. In central Italy, basinal sections close to acarbonate platform margin are studied. The southern Germany sections are located on acarbonate ramp. The location of the sections, from shelf to the basin, enable the spatial variationof the nannofloral assemblages to be compared. Stratigraphic control of the studied sections isbased on ammonites biozonations and in south-east ofFrance, integrated ammonites anddinoflagellates biostratigraphy.
In the studied sections the oligotypic assemblage is dominated by a half dozen of
specimens ofthe genus Watznaueria. The most significant abundance fluctuations are observedfor W barnesae, W britannica and W manivitae. As these species are very diagenesis resistant,
we believe their fluctuations reflect primary palaeoceanographic variations. Statistical analyses
applied to the abundances and distributions of the most common species will allow the main
factors influencing narmoplankton distribution during the Middle-Late Jurassic to be depicted,
such as sea level fluctuations, changes in productivity of the oceans and more general global
environment changes.

Community Structure of Living Coccolithophore in the Central and Western PacificKyoko Hagino
Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University
North 10, West 8, Kita-ku, SAPPORO, 060 JAPAN.
E-mail: hagino@strati.sci.hokudai.ac.jp. Tel. +81 (0)11 716 2111 (ex. 3519)

Vertical distribution of coccolithophores was investigated at 17 stations in the central andwestern Pacific Ocean. A total of 146 taxa, including a new species, was identified from 139
water samples studied.
Many species exhibited vertically constrained distribution, and the floral composition wasstrongly controlled by the stratification of the water column. In the well stratified water column,
the floral structure was stratified to three vertical zones. Umbillicosphaera spp., Discosphaera
tubifera, Rhabdosphaera clavigera, Umbellosphaera spp. and many holococcolith-bearing
species were the major components ofthe upper photic zone. Emiliania huxleyi, Gephyrocapsa
ericsonii and Gephyrocapsa oceanica were common throughout the entire photic zone, but wereparticularly abundant at the thermocline, thus defining the middle photic zone. Dolithos fragilisthat dwells in the middle to lower photic zone, was more concentrated in the thermocline. On theother hand, Algirosphaera spp., Florisphaera profunda and Gladiolithus flabellatus occurredexclusively below the thermocline. In the weekly stratified water column, the flora was divided
into two vertical zones. 0. fragilis, E. huxleyi and G. oceanica were abundant in the upper photic
zone, and F. profunda, Algirosphaera spp. and G. jlabellatus were constrained below thethermocline.
In the well mixed water column where no thermocline could be observed, the floral
stratification was very weak, and some of lower-photic inhabitants occurred in the shallow depth(up to 30m).

Calcareous Nannoplankton Biostratigraphy of the
Coast Basin ofTogo, West Mrica
Boburnj) Hamrsrnid 1 and Yawoa da Costa2
1

CZECH REPUBLIC. E-mail: hamrsmid@mnd.cz
2
TOGO.

The Coast Basin ofTogo with the territory of33.00km21ies in the southern part ofTogo(West Africa) and extends into the offshore part of the Atlantic. Calcareous nannoplankton
assemblages from 10 wells drilled in the onshore part of the basin down to the depth of 160 m
were analyzed for the first time. Despite of the frequent lack of markers and very bad
preservation of nannofossils, three sedimentary cycles were clearly recognized., The oldest
sediments contained Arkhangelskiella cybiformis, Ceratolithoides aculeus <90°, Lithraphidites
quadratus ... documenting their Maastrichtian age. Next transgression started in the Upper
Paleocene (NP 7 -with Discoster mohleri, Biantolithus sparsus, Cruciplacolithus frequens,
Fasciculithus tympaniformis, Heliolithus cantabriae, etc.) and continued till above the
Paleocene/Eocene boundary (lower part ofNP 10 - Tribrachiatus bramlettei, Rhomboastercuspis, Discoaster binodosus, Discoaster salisburgensis ... ). The next transgression reached thearea under study in the middle Eocene (NP 15- Nannotetrina cristata, Chiasmolithus gigas,
Discoaster barbadiensis, Helicosphaera seminulum ... ) and went on till the Middle/Upper Eocene
boundary (NP 17/NP 18- Helicosphaera compacta, Reticulofenestra umbilicus, Helicosphaera
reticulata, Cribrocentrum reticulatum, Discoaster saipanensis ... ). The above laying sediments(mostly continental sands, sandstones and siltstones) were barren and their stratigraphicalposition has not been documented.

Coccolith Assemblages Along anE-W Transect North of the Canary Islands (29°N):
Comparison Between Sediment, Sediment Trap and Plankton Samples
J. Henderiks\ J. Bolhnann\ T. FreudenthaJ2· H. Meggers 2 , C. SprengeJ2, and HR Ibierstein 1
1Geological Institute, ETH-Zentrum, CH-8092 ZURICH, SWITZERLAND. E-mail: thiersten@erdw.ethz.ch2
Geoscience Department, University ofBremen, Postfach 330440, D-28334 BREMEN, GERMANY

Coccoliths, as a major component of carbon deposited in the North Atlantic Eastern
Boundary Current system, are investigated to quantify fluxes and to reconstructpaleoceanographic and paleoclimatic changes in this area.
The quantitative changes in species composition of coccolith assemblages may be
indicative of changes in temperature, surface water fertility and preservation. In the Eastern
Boundary Current system, the major gradients of fertility, the gradient of temperature, and thepossibly disturbing influence of carbonate dissolution will be investigated on a dispersed set of
surface sediment assemblages. Preservational effects should be identifiable by a comparison withassemblages collected in sediment traps of the nearby ESTOC mooring and plankton standing
stock studies. Downcore analyses of coccolith assemblages in 3 gravity cores (GeoB 4242,
29°40.5N, l7°53.3W; GeoB 4241, 29°10.0N, l5°27.2W; GeoB 4240, 28°53.3N, 13 o 13.5W)
taken along a 500km long E-W transect north of the Canary Islands will be used to assess
temporal and spatial changes of the crucial oceanographic parameters over the past 125ka. This
will be attempted by population counts and morphometric measurements of keystone taxa. The
morphometric measurements may reveal highly accurate temperature or fertility correlations, if
they can be calibrated in plankton samples, which were taken seasonally at different depth levels.
Current results of abundance determinations of coccoliths in surface sediments reveal ageneral dominance of Emiliania huxleyi, followed by Florispaera profunda. The E-W fertility
gradient is represented by changes in the morphology of the gephyrocapsid-group. Size andbridge angle increase towards the coastal area.
Assemblage compositions recorded in sediment traps at 976m water depth (ESTOC
station; September 1994 - October 1995) are similar to the observations in the surface sediment
below. E. huxleyi coccoliths dominate throughout the sample period, with a seasonal variabilityof the total fluxes.
The plankton samples analyzed so far, show seasonally highly variable compositions withperennial dominance of G. ericsonii, and seasonal fluctuations of E. huxleyi and V. tenuis in theupper photic zone (0-1 OOm water depth), and F. profunda in the lower photic zone (1 00-200m
water depth).

Cocolithophorids from the Subtropical Mexican Pacific(West Coast ofBaja California, Mexico)
Dayjd lJriel Hern;indez-Becerril, Y. Ramirez and E. Bravo-Sierra
Laboratorio de Ecologia de Pesquerias, Instituto del Mar y Limnologia (ICMyL)
UNAM, Apto. Postal 70-305, MEXICO. E-mail: duhb@hp.fciencias.unarn.mx

Studies on coccolithophorids in Mexico are rather scarce, mainly due to lack of training
in species identification, and the traditional methods for studying marine phytoplankton (e.g.
collection, preservation and analysis). There are a couple of papers on floristics of this group,
one made in the Gulf of Mexico and the other is a list of species from the Gulf of California.
Bottle samples (4 lt.) were taken various depths, in perpendicular transects along the west coastofBaja, California and Magdalena Bay, Mexico, considering neritic, intermediate and oceanic
zones. Environmental variables were measured, such as dissolved oxygen, temperature and pH.
A total of 32 samples were studied by optical and scanning electron microscopy, yielding 20
species identified and another 4 taxa not fully identified. The coccolithophorid flora is typicaltropical - subtropical. The highest richness of taxa was observed in intermediate and oceanic
stations. Gephyrocapsa spp. Dominated in number at most stations. We report seven newrecords for the Mexican Pacific.

Variations in South Atlantic Calcdinoflagellate Associations Since the Late Cretaceous
Tania Hj]debrand-Habel & Helmut Willems
Department of Earth Sciences, University ofBREMEN, GERMANY
E-mail: hiha@micropal.uni-bremen.de; willems@micropal. uni-bremen.de

For the first time, Maastrichtian to Miocene calcdinoflagellate associations of several
South Atlantic DSDP/ODP sites have been examined. The assemblages mainly consist oflongranging forms, fluctuating qualitatively and quantitatively in distinct stratigraphic patterns.
Generally, the Maastrichtian is characterized by stable calcdinoflagellate associations,exhibiting high percentage occurrences of obliquely and radially structured calcareous
dinoflagellate cysts. Although no accelerated rates of extinctions are evident at the CretaceousTertiary boundary, the broad species spectrum is modified by an extreme dominance of thetangentially structured Operculodinella operculata, which occurs in high abundances especiallyin NP1-NP3. The bloom ofthis species has been reported from numerous localities andapparently had a world-wide distribution. Comparable changes concerning the nature of theassemblage across the Cretaceous-Tertiary boundary had been described by Flitterer (1990) fromthe Weddell Sea and by Kienel (1994) from the Boreal of Europe. During Paleocene and partly
Eocene, the dominance of various species of tangentially structured calcareous dinoflagellates
persists. Only in the course of Oligocene and Miocene, oblique and radial wall structures become
prominent again. Other than in the Recent, significant percentage occurrences of Thoracosphaera
have not been recognized in the examined stratigraphic interval.
Although the particular factors controlling the stratigraphic differentiation of
calcdinoflagellate associations remain ambiguous, changes evidently correspond to variations in
the environmental conditions.

REFERENCES:
FOITERER, D. K. ( 1990): Distribution of calcareous dinoflagellates at the Cretaceous-Tertiary boundary of Queen MaudRise, Eastern Weddell Sea, Antarctica (ODP Leg 113). - Proc. ODP, Sci. Results, 113 : 533-548.
KIENEL, U. (1994): Die Entwicklung der kalkigen Nannofossilien und der kalkigen Dinoflagellaten-Zysten an der

Kreide/Tertiiir-Grenze in Westbrandenburg im Vergleich mit Profilen in Nordjiitland und Seeland (DK). Berliner geowiss. Abh. (E), 12 : 1-87.

Variations in Surface Water Mass Conditions Along the North East
Atlantic Fringe as Evidenced by Late Quaternary Calcareous Nannoplankton
Nicky Hine
Earth Sciences Department, University of Sheffield, Sheffield, S3 7HF, UK.
E-mail: n.m.hine@sheffield.ac.uk

Calcareous nannoplankton from Late Quaternary sediment cores have been analyzed.
Cores are sited along the northeastern Atlantic margin of the British Isles and follow a northeasterly to south-westerly trend from the Faeroe-Shetland Channel in the north, along theHebridean Platform and into the Rockall Trough in the south.
All samples are assigned a Late Quaternary age based on their calcareous nannoplankton
assemblages together with additional foraminifera and dinoflagellate cyst data. There has been
no absolute dating of the cores.
The calcareous nannoplankton assemblages are of low diversity and range in abundance
form rich to barren. The cores are characterized by a succession of calcareous nannoplankton
assemblages which are alternately dominated by a single species or are barren. Commonlyrecorded species include Emiliania huxleyi, Coccolithus pelagicus, Calcidiscus leptoporus,
Syracosphaera spp. and large and small Gephyrocapsa. Not all cores are considered to contain acomplete record with hiatuses developed to varying degrees.
The down-core variations in the nannoplankton assemblages reflect the dynamic
oceanographic conditions which prevailed throughout the Late Quaternary period. They suggest
a number of fluctuations in the strength of the North Atlantic Current during the time the cores
were deposited with a consequent change in the oceanographic regime of the North East Atlantic
Ocean. These changes are associated with mass wastage of the North East Atlantic margin.

On the Environmental Affinity of Calcareous Dinoflagellates in Late Quaternary
Sediments of the Tropical Atlantic.G...lliill, B. Karwath, C. Riihlemann, K.A.F. Zonneveld,and H. Willems
Fachbereich Geowissenschaften, Universitiit BREMEN, GERMANY
E-mail: hoell@micropal.uni-bremen.de; karwath@zfn.uni-bremen.de; willems@micropal. uni-bremen.de

Environmental affinities of calcareous dinoflagellates have been investigated for the last
140 ka by comparing two sediment cores: one from the highly productive eastern Atlantic
equatorial divergence zone and the other one from the low productivity western tropical Atlantic.
Pronounced differences in palaeoproductivity between the two sediment cores are indicated byhigh and variable organic carbon accumulation rates in the east, in contrast to relatively constantand low values in the west. Calcareous dinoflagellates show just the opposite pattern: highabundances in the west and lower in the east. At the equatorial divergence zone, temporalvariations of calcareous dinoflagellate abundance and organic carbon accumulation rates show,
for the most part, an inverse relationship. High calcareous dinoflagellate contents coincide withlow organic carbon accumulatiGm rates and vice versa. In the investigated region and timeinterval, enhanced production of calcareous dinoflagellates can be correlated to periods of
reduced palaeoproductivity related to relatively stratified conditions of the upper water column.

Morphometric Analysis of the Broinsonia parca plexus Across the Santonian-CampanianBoundary
A Howard 1•2 , P.K Bown\ J.A. Burnete and J.R. Young2
1

Department of Geological Sciences, University College London, Gower Street, London,
WClE 6BT, UK. E-mail: a.howard@ucl.ac.uk
2
Palaeontology Department, The Natural History Museum, Cromwell
Road, London, SW7 5BD, UK. E-mail: jy@nhm.ac.uk

Calcareous nannofossil biostratigraphy and palaeoceanography is fundamentally reliant uponpractical, precise and reproducible taxonomic definition. Most established phylogenetic models andbiostratigraphic datum events are based on subjective observations of gross morphology, despite thewell illustrated problems of intraspecific variation and gradualistic change from the fossil record.
Recently, relatively simple measurements of coccolith morphology have been utilized to provide
effective quantitative approaches to taxonomy and aid in the recognition ofbiostratigraphic datum
events (e.g. Young, 1990; Bralower and Parrow 1996; K.nappertsbusch et al., 1997).
Introduced here is the application oflight-microscope-based image-capture techniques (seeYoung et al., 1996) to perform a detailed morphometric analysis of the Broinsonia parea plexus andassociated Arkhangelskiellaceae across the Santonian/Campanian boundary from two geographicallydisparate sites; ODP Leg 119, hole 738C, Kerguelen Plateau and Scratchells Bay, Isle ofWight, UK.
The FO of Broinsonia parca parca is an important biostratigraphic datum utilized in both low
latitude (e.g. Bralower et al., 1995), high latitude (e.g. Watkins, et al. 1996) and global (Burnett in
Bown, in press) calcareous nannofossil zonation schemes. Currently, precise definition of the species
concept of B. parca parca is lacking in practice despite a varied literature (e.g. Hattner et al., 1980;
Crux, 1982; Wise, 1983). Morphometric techniques are applied to provide a quantitative taxonomic
and stratigraphic framework for the evolution of the Broinsonia parca plexus across the
Santonian-Campanian boundary. Work herein represents preliminary results ofPh.D. research.
RERFERENCES:
Burnett, J.A. (in press), Upper Cretaceous, in Bown (Ed.), Calcareous Nannofossil Biostratigraphy. Chapman and Hall, inpress.
Bralower, T.J., Leckie, R.M., Sliter, W.V. and Thierstein, H.R., 1995. An integrated Cretaceous microfossil
biostratigraphy. SEPM Special Publication No. 54, p. 65-79.
Bralower, T.J. and Parrow, M., 1996. Morphometries of the Palaeocene coccolith genera Cruciplacolithus, Chiasmolithus,
and Sullivania: a complex evolutionary history. Paleobiology, 22(3), 1996, p. 352-385.
Crux, J.A., 1982. Upper Cretaceous (Cenomanian to Campanian) calcareous nannofossils, in Lord, A.R. (Ed.), A
Stratigraphical Index of Calcareous Nannofossils: Chichester (Ellis Horwood), p. 81-135.
Hattner, J.G., Wind, F.H. and Wise S.W., 1980. The Santonian/Campanian boundary: Comparison ofnearshore-offshore
calcareous nannofossil assemblages. Cah. Micropaleontol., No. 3 (1980), 9-26.
Knappertsbusch, M., Cortes, M.Y. and Thierstein, H.R., 1997. Morphologic variability ofthe coccolithophorid
Calcidiscus leptoporus in the plankton, surface sediments and from the Early Pleistocene. Marine
Micropalaeontology 30 (1997), p. 293-317.
Watkins, D.K., Wise, S.W., Pospichal, J.J. and Crux, J., 1996. Upper Cretaceous calcareous nannofossil biostratigraphy
and palaeoceanography of the Southern Ocean, in Moguilevsky, A. and Whately, R. (Eds), 1996. Microfossils
and Oceanic Environments, University of Wales, Aberystwyth Press, p. 355-381.
Wise, S.W., 1983. Mesozoic and Cenozoic calcareous nannofossils recovered by Deep Sea Drilling Project Leg 71 in the
Falkland Plateau region, southwest Atlantic Ocean, in Ludwig, W.J., Krasheninnikov, V.A., et al., Init. Repts.
DSDP, 71: Washington (U.S. Govt. Printing Office), p. 481-550.
Young, J.R., 1990. Size variation ofNeogene Reticulofenestra coccoliths in Indian Ocean DSDP cores. Journal of
Micropalaeontology, 9, p. 71-86, London.
Young, J.R., Kucera, M. and Chung, H-W., 1996. Automated biometrics on captured light microscope images ofcoccoliths of Emiliania huxleyi, in Moguilevsky, A. and Whately, R. (Eds), 1996. Microfossils and Oceanic
Environments, University of Wales, Aberystwyth Press, p. 261-277.

A Preliminary Nannofossil Biostratigraphy of the Jurassic of the Rankin Platform andDampier Sub-basin on the North West ShelfofWestern Australia
Richard Howe
AUSTRALIA. E-mail: rhowe@cyllene.uwa.edu.au

Preliminary analysis of sidewall cores from two petroleum exploration wells on the
Rankin Platform (Brigadier #1 and Gandara #1) and one well in the Dampier Sub-basin (North
Rankin #4) has revealed that the Lower to Middle Jurassic sequence in these wells contains low
to moderate abundance assemblages of poorly to moderately preserved calcareous nannofossils.
These assemblages represent the first record of in situ Early and Middle Jurassic nannofossils
from Australia, other than the early Bajocian assemblage recorded from the Newmarracarra
Limestone in the onshore Perth Basin by Shafik (1994).
Nannofossil diversity is moderate, with more than 40 species recorded. Most of theassemblages are dominated by Schizosphaerella punctulata and species of Lotharingius. The
oldest assemblages belong to Subzone NJ4a, of early Pliensbachian age, according to thecorrelations of de Kaenel et al. (1996) and Bown (1996). These assemblages are distinctly
Tethyan in character, as they contain Mitrolithus elegans and M lenticularis. An unconformity
related to the onset ofrifting on the North West Shelf separates these assemblages fromoverlying assemblages belonging to NJ6-9, ofToarcian to Bajocian age. Mitrolithus }ansae ispresent in assemblages belonging to Zone NJ6, but declines in abundance upwards, suggesting a
progressive decline in Tethyan influence.
Discovery of these assemblages will hopefully add significantly to the sparse record ofLower and Middle Jurassic nannofossils from the southern hemisphere, and the Australian regionin particular.
REFERENCES:
Bown, P. R. (1996). Summary chart of Jurassic nannofossil biostratigraphy. Journal ofNannoplankton Research 18,

9.
de Kaenel, E., Bergen, J. A., and von Salis, K. ( 1996). Jurassic calcareous nannofossil biostratigraphy of western
Europe. Compilation of recent studies and calibration ofbioevents. Bulletin de la Societe geologique deFrance 167, 15-28.
Shafl.lc, S. (1994). Significance of calcareous nannofossi1-bearing Jurassic and Cretaceous sediments on the Rowley
Terrace, offshore northwest Australia. Australian Geological Survey Organisation Journal of Australian

Geology and Geophysics 15, 71-88.

Nannofossils from a Lower Miocene Core of Puerto Rico
Iing C Huang

EEC/Biostratigraphy GP3-307C Houston, Texas USA
E-mail: tchuang@earthlink.net

In search for more useful nannofossil events to enhance biostratigraphic resolution of thelower Miocene, Core NC-4 drilled by USGS in north Puerto Rico was studied for nannofossils.
The studied section is lower Miocene in the Sphenolithus belemnos Zone (NN 3) and lower.
Further subdivision of the section into NN 2 and NN 1 is very difficult using standard zonal
events ofMartini (1971). The last occurrence datum ofTriquetrorhabdulus carinatus, which
defines the top ofNN 2, has not been well calibrated with paleomagnetic stratigraphy (Berggren
et al., 1995), and a recent study (Olafsson, 1989) proved that it actually occurs higher at a
stratigraphicallevel correlative with the top ofNN 3 or even higher. The top ofNN 2, defined by
the first occurrence ofDiscoaster druggii, has been hard to place as well, because this marker isgenetically closely related and morphologically gradational to Discoaster calculosus andDiscoaster deflandrei.
Despite the difficulty in assigning standard zones for the section, the following eventswere identified in this study. They are considered useful for subdivision of the section. These in
downhole order are:
•
•
•
•
•
•
•

Last occurrence ofOrthorhabdus serratus at 1357' (in NN 3).
Last occurrence of Sphenolithus cf. S. heteromorphus at 1386'.
Last occurrence ofTriquetrorhabdulus auritus at 1450' (in NN 2).
Last common occurrence ofSphenolithus cf. S. heteromorphus at 1450'.
First occurrence ofSphenolithus cf. S. heteromorphus at 1518'.
First occurrence of Orthorhabdus serratus at 1548'.
Last occurrence of Helicosphaera recta at 1732' (in NN 1 ?).

Throughout this study, an object of uncertain origin was found rare but persistent below
1532' to 1750'. The "UFO" has five segments of crystallite, which are dark in polarized light.
Four of them are connected to form a rectangle, and the fifth one is a bar that runs parallel to the _short axis of the rectangle and divides the object into two equal halves. Its taxonomic affinities
are unknown.
Another interesting form, Sphenolithus cf. S. heteromorphus, appears to have a shortrange in the lower Miocene. It occurs rarely near its top occurrence at 1386', but commonly andpersistently from 1450' to 1518'. This species is different from Sphenolithus heteromorphus inbeing slightly asymmetrical and having a longer cone. A similar form has been documented by
Peleo-Alampay and Wei (1995, plate 1, figs. 14-15, 18-19) from the north Atlantic DSDP site563, and by Jiang and Watkins (1992, plate 3, figs. 16-18) from the Gulf ofMexico. Although it
occurs sporadically in both regions, these occurrences were recorded about the same stratigraphic
lposition as noted in this core. It may be a potential age marker, which has been underdocumented.

Architecture of Braarudosphaera bigelowii (coccolithophorid): A Marine Planktonic Alga
Holding Clues to Quasicrystalline Symmetry
Syed A Jafar
Birbal Sahni Institute ofPalaeobotany, 53, University Road,
Lucknow 226 007, INDIA

The cysts of golden-brown alga Braarudosphaera bigelowii, representing the resting
phase with biomineralized Calcite skeleton, display quasicrystalline dodecahedra! symmetry(Euclidean =flat, Elliptic= convex, Hyperbolic= concave) 1-3 with radial pentalith sutureintercepts closely oscillating across golden mean ratio: (sq.rt 5 + 1)/2. Studies under the lightand scanning electron microscope reveal finely laminated nature of each of the 12 regularpentalith plates consisting ofmicrocystallites of mineral Calcite (CaC03) with Penrose
pentagonal rotational symmetry 4 , in terms ofC-axis orientation of five optically distinct units(Fig. I). Dodecahedra! symmetry is expected to be discovered among metallic alloys, which so far
have only revealed fivefold icosahedral symmetry.
The dodecahedra! cyst of B.bigelowii, represent one of the most perfectly known Platonic
bodies (Universe) of ancient mathematicians5-6 • The quasiperiodic tiling of the three-dimensional
space is also known from different organizational level of a variety ofbiologic entities using avast array ofbuilding material, viz., radiolaria (hydrous- silica), coccoliths (biogenic Calcite),pollen-spores (organic polymers)7-8, viruses (nucleoprotein) including more recent andremarkable quasicrystalloid 5-fold symmetry discovered in low density-high strength Mn-Al
alloys, optically condensed matter and all-carbon Buckminsterfullerene molecules 9 •Thermodt;;namics of quasiperiodic symmetry in living and non-living system has yet to be
fully understood 0, but in case of abundant quasicrystalline microbiogenic particles invisible to
naked eye, the golden mean seems to control the aesthetically harmonizing icosahedraldodecahedral patterns and forms, produced under subdued gravitational force, but major
influence of surface tension, brownian movement and electrical forces. Does nonperiodicity
signifies dominant feature ofliving and an exceptional trait of non-living system?
REFERENCES

1. JAFAR, S.A. (1975): Elsevier-North Holland Publishing Company, Amsterdam-New York.
2. THuRsTON, W.P. AND WEEKS, J.R. (1984): Sci., Am., 251(1),108.
3. GARDNER, M. (1977): Sci. Am., 236, 110.
4. PENROSE, R. (1978): Eureka, 39, 16.
5. STEVENS, P.S. (1974): Little Brown and Company, Boston-Toronto.
6. BRIESKORN, E. (1983): Friedr. Vieweg und Sohn, Braunschweig/Wiesbaden.
7. KEDVES, M. (1989): Acta Biol. Szeged., 35, 53.
8. UENO, J. (1983): Japanese J. Palynol., 29(2), 39.
9. HARIHARAN, Y. (1992): Curr. Sci., 63(1), 25.
10. GOLDMAN, A.l. (1996): Am. Sci., 84, 230.

Fig. I. A model of an isolated pentalith plate of B. bigelowii (proximal view, tilted away from observer; diameter
ca.5t-t). The most commonly observed optic orientation of Calcite rnicrocrystallites is shown in sectors 1 & 2 andrare one in sectors 3 & 4. The dip and orientation of C-axis is indicated for each pentalith segment behaving as asingle crystal and normal lattice of Calcite. After initial nucleation of dodecahedra! framework, the plates are
permitted to grow in thickness only inwards, to maintain constant relativity of growth and similar line segment
ratios on both proximal and distal face (Sector 3; a: 2a = x: 2x ). Each of the five polyhedral Calcite units (sectors
1-5) could be conceived to have been produced by truncation of a larger Penrose golden rhombus with angles of

108° -7r.

Coccolith Palaeoecological Interpretations from an Upwelling Region
Off NW Mrica (ODP 658C) During the Last 130 kyrs
R.W. Jordan 1 and M. Cacbao 2
1

Dept. of Earth & Enviromnental Sciences, Fac. Science, Yamagata Univ., Yamagata, 990 JAPAN.
E-mail: sh081 @kdsal.kj.yamagata-u.ac.jp
2Dep. Geology, Fac. Sciences Lisbon Univ., Rua Escola Politecnica, no 58, P-1294 Lisboa, Codex, PORTUGAL
E-mail: mcachao@fc.ul.pt

Sediments beneath a permanent upwelling cell were drilled and recovered for the firsttime during ODP Leg 108 and provide a long term record ofupwelling history offNW Africa.
Previous studies on samples from site 658C used the coccolithophorid-based U\ 7 proxy torecognize Heinrich events and characterize the SST regime during isotope stages 1 to 6 in thesesediments off Cap Blanc (JORDAN et al., 1996; ZHAO et al., in press).
The coccolith data was converted into a matrix of 84 samples by 16 taxa + 3 parameters.
The parameters were 'Others' (which excluded the dominant species Emiliania huxleyi,
Gephyrocapsa spp. and Florisphaera profunda ), the upper photic zone flora (UPZ; which
included Umbellosphaera spp., Neosphaera coccolithomorpha, and Rhabdosphaera spp.) andUk37 -estimated SST. This matrix was subsequently processed through a multivariate statisticalmethod (Factor Analysis) and four factors were extracted. The factors explain 60.5% of the total
variance.
Factor 1 (with 29.6% variance) clearly distinguishes SST together with F. profunda andSyracosphaera spp. on the positive axis, from Calcidiscus leptoporus and Gephyrocapsa
muellerae (and to a lesser extent Calciosolenia murrayi and Gephyrocapsa aperta) on thenegative axis.
Factor 2 (with 13.3% variance) defines Gephyrocapsa oceanica, Coccolithus pelagicus,
Umbilicosphaera sibogae and 'Others' on the positive axis, and the UPZ flora, Umbellosphaera
spp. and Calciosolenia murrayi on the negative axis.
Factor 3 (with 8.5% variance) distinguishes between E. huxleyi, G. oceanica,
Syracosphaera spp., Helicosphaera spp., C. pelagicus, C. murrayi, N. coccolithomorpha, U.
sibogae var.foliosa and SST on its positive axis from G. aperta, G. muellerae and C.
leptoporus on its negative axis.
Factor 4 (with 8.1% variance) distinguishes the UPZ flora, U. sibogae var.foliosa, N
coccolithomorpha, Umbellosphaera spp., C. murrayi and G. oceanica on its positive axis from
Helicosphaera spp., C. pelagicus and G. muellerae on its negative axis.
These assemblages are not so easy to interpret, but there are a few patterns which may be
explained. There seems to be a clear distinction between subtropical and temperate floras. For
instance, G. muellerae, G. aperta and C. leptoporus do not appear on the same side of theanalysis as the subtropical species. This may be based on simple warm I cold water preferences,as clearly seen in JORDAN et al. (1996) in their plots ofUk"37-derived SST against the relativepercentages of various species.
We believe that the downcore distributions of these assemblages result from changes in
the offshore extent of the upwelling cell, in association with the periodic southward migration oftemperate species (e.g. G. muellerae) during cooler periods (and during most Heinrich events). It
is our opinion that different assemblages exist at varying distances from the upwelling centre,
and that changes in the strength and direction of the prevailing winds (i.e. upwelling intensity)
control which assemblage sediments out over the core site. The species composition of thesezones will be discussed in our presentation.

REFERENCES:JORDAN, R.W., ZHAO, M., EGLINTON, G. & WEAVER, P.P.E. (1996). Coccolith and alkenone stratigraphy andpalaeoceanography at an upwelling site offNW Africa (ODP 658C) during the last 130,000 years. In:
Microfossils and Oceanic Environments (Eds. Moguilevsky, A. & Whatley, R.), University of Wales,
Aberystwyth-Press,, U.K.: 111 - 130.
ZHAO, M., HASLETT, S.K., JORDAN, R.W., KNAACK, J.J., SARNTHEIN, M., TEECE, M. & EGLINTON, G.
(1998). Multi-proxy sedimentary records ofupwelling and wind systems offNW Africa over the last 35,
000 years. Earth and Planetary Science Letters, in press.

Seasonality of Living Coccolithophorids off the Puerto Rican Coast
Ric W Jordan 1 and Amos Wintez2
1

Dept. of Earth & Environmental Sciences, Fac. Science, Yamagata Univ., Yamagata, 990 JAPAN.
E-mail: sh081 @k:dsal.kj .yamagata-u.ac.jp
2
University of Puerto Rico, Marine Sciences Dept., Mayaguez, PR, 00681 USA.
E-mail: a_winter@rumac.upr.clu.edu

Phytoplankton samples were collected biweekly from a number of depths at a fixedstation off the coast ofPuerto Rico over a four year period (1992-1995). Here the results from1995 (samples taken only between Jan.-May) are presented, although observations from otheryears will also be discussed. For each filter sample the microplankton composition was counted
and the coccolithophorid species assemblages identified. The 1995 results show that the diatom
contribution was highest during January and February, but from March-May the diatoms(especially the centrics) decreased in relative abundance whilst the coccolithophorids increased.
However, the coccolithophorids always maintained a dominant or eo-dominant assemblage in the
middle to lower photic waters regardless of what was happening in the surface waters above. On
the other hand, dinoflagellates never constituted more than 10% at any depth, which is a little
surprising considering that near to the coast is a region famous for exceedingly high numbers of
dinoflagellates. There is also evidence that material (e.g. epiphytic diatoms, chrysophyte cysts,
pollen) from the Puerto Rican coast or mainland has been transported to the shelf area atparticular times of the year.
The coccolithophorid community was distributed vertically into the three classical photic
zones, including an easily recognizable middle photic zone. The revised zonal assemblages will
be discussed in detail during the presentation. The general trend is a change from an assemblage
dominated by either E. huxleyi or G. oceanica (without a collar) in the January to early Marchsamples, to one dominated by D. tubiferafi\, U. irregularis and holococcolithophorids in theupper photic zone, M elegans and A. q;;Qdricornu in the middle photic zone, and F. profunda
var. profunda in the lower photic zone from late March to May. In this latter period G. oceanica
almost completely disappears from the counts(= <1% in May), although E. huxleyi also ·markedly declines at all depths its highest numbers are at the base of the upper photic zone
(around 60-75m). F. profunda was the dominant species between 100-125m on only threesampling occasions (on 13th February, 24th March and lOth May). The absence/low percentageof this species (and other lower photic species) in the other deep samples, probably indicates thata deepening of the nutricline occurred, as in all cases there are significant amounts of middle
photic zone species present.
These results show that the Puerto Rican shelf waters may still exhibit seasonality eventhough they are considered oligotrophic and permanently stratified. Observations from othersamples within the four year sample has shed light on the seasonality and annual cyclicity of thephytoplankton from this subtropical area.

The Mid-Late Cretaceous and Early Tertiary Calcareous Nannofossils; Tanzania
Amjna I S Karega
Tanzania Petroleum Development Corporation, Box 5233, DarEs Salaam, TANZANIA.
E-mail: tpdcexploration@raha.com

Fifty-three species of nannofossils were recovered from eleven up hole samples collectedduring the running of seismic surveys in Ruvuma Basin Southern, Tanzania. Samples were
subjected to standard nannofossils preparations. Smear and centrifuged slides were prepared foreach sample. Samples were studied under light (LM) and Scanning Electron Microscope (SEM)
for nannofossil assemblages.
·
The samples were found to contain a significant amount of nannofossils, ranging in age
from Mid-Late Cretaceous and Tertiary. SEM and LM of well preserved specimens were taken.
A number of zones were identified based on the presence of zonal marker species. The claystones
and shales of the studied Cretaceous interval have a high diversity of calcareous nannofossils.
While the studied Tertiary section consisted of argillaceous and carbonate deposits a high influxof calcareous nannofossils were observed.

Environmental Affinities of Thoracosphaera heimii in Field and Laboratory Studies Preliminary Results
Britta Karwatb, Dorothea Janofske and Hehnut Willems
University ofBREMEN, GERMANY. E-mail: karwath@zfn.uni-bremen.de;janofske@micropal.uni-bremen.de; willems@micropal.uni-bremen.deThoracosphaera heimii is a marine, planktonic dinophyte. It is phototrophic and the only
dinoflagellate known to have a predominant calcareous coccoid stage in its vegetative life phase.
The association of calcareous dinoflagellates in the plankton and in sediment cores ischaracterized by the overwhelming dominance ofT. heimii. Recent work on sediment coresfrom the tropical Atlantic hints at a possible relationship between an increased abundance ofT.
heimii in sediment core material and decreased productivity under oligotrophic stratified
conditions of the upper water column. To gain a better insight into the environmental affinitiesof this species, the spatial distribution ofT. heimii was studied on a cruise from Las Palmas(Canaries) to Recife (Brazil) (26th January to 1st March). Samples were collected from the watercolumn, ranging from 10 m to 50 m depth. Additionally to the field studies, a clone ofT. heimii(CCMP 1071) has been cultured under controlled laboratory conditions. To this end, the clone
was held in a temperature gradient from 35.5 to 7.5 °C. Cultures were also tested on theirsalinity tolerance.

Coccolithophore Response to Changing Late Quaternary Paleoceanography in the
Equatorial Atlantic Ocean
Hanno Kjnkel and Karl Heinz-Baumann
FB Geowissenschaften, Universitat BREMEN, GERMANY.
E-mail: hkinkel@mail.sedpal. uni-bremen.de; khb@mail. sedpal. uni-bremen.de

In order to reconstruct the response of coccolithophores to changing paleoceanographic
conditions, we investigated a set of surface sediment samples and three sediment cores from theEquatorial Atlantic. Present day surface water oceanography in this area is characterized byseasonal upwelling between 5°N and 10°S which stretches out from 10°E to 25°W. The driving
mechanism for the upwelling is the strength of the tropical easterlies which are modulated byannual and long term insolation variations. Strong tropical easterlies shallowing of both
thermocline and nutricline in the East resulting in a large nutrient flux to the upper photic zone
and increased phytoplankton productivity. Outside the upwelling area, the thermocline andnutricline are deep resulting in a oligotrophic well stratified surface layer. The biogeographicaldistribution of coccolithophores in surface sediments reflect the situation of the overlying water
masses, although the coccolithophore assemblages are heavily altered when settling through thewater column. Eutrophic conditions in the photic zone are relatively well represented in surface
sediments with highest abundances of E. huxley beneath the upwelling area where they also
dominate the living assemblages. In contrast surface sediments underneath oligotrophic areas are
dominated by the Lower Photic Zone taxa (LPZ) F. profunda and G. jlabellatus due to strong
dissolution of U irregularis and U. tenuis, whose abundances are reduced from up to 100 % of
the living assemblage to about 5% ofthe surface sediment assemblages. The abundance of the
LPZ taxa therefore enables us to reconstruct paleo - thermocline and nutricline depth andproductivity. We present a reconstruction of surface water structure and productivity withcoccolithophores for three sediment cores from the southern, central, and western Equatorial
Atlantic of the last 140,000 years. The coccolithophore records in the southern and central
Equatorial Atlantic show a strong cyclicity within the precession band of orbital forcing as thetropical easterlies are negatively correlated to the insolation at 15° N. Basin wide tilting causes a
deepening of thermocline and nutricline in the west when a shallowing due to increased wind isreached in the east. Therefore the western sediment core shows an opposite trend in the
coccolithophore record in comparison to the southern and central Equatorial Atlantic.
I 11'1

Calcareous Nannoflora Response to Termination 11 at 45°-53°N (Northeast Atlantic)
Anna Lototskaya, Patrizia Ziveri, Gerald M. Ganssen, and Jan E. van Hinte

Geomarine Centre, Faculty ofEarth Sciences, Free University, De Boelelaan 1085, 1081 HV Amsterdam, THE
NETHERLANDS. E-mail: lota@geo. vu.nl.

Termination II (glacial to interglacial transition from oxygen isotope stage 6 to stage 5) is
considered to be one of the most rapid and abrupt climatic changes during the Late Quaternary.
Our high resolution geochemical and floral study ofthe 140-100 ka BP interval in the northeast
Atlantic cores T90-9P (45 °N, 25 °W) and T90-2P (53 °N, 20°W) shows that Termination II (135125 ka BP) occurred in two steps of drastic changes, interrupted by a short period of stability,and followed by at least 25 ka of relatively stable, interglacial conditions, traditionally referred toas the Eemian age (substage 5.5).
For ~e core T90-9P, an export production proxy based on coccolith accumulation rate
(number/cm ka), and supported by carbon isotope record ofplanktic foraminifera Gs. ruber,shows higher values during the Ef9!1ian than duri~ glacial stage 6 and interglacial substage 5.4,
with the maximum values (70x10 coccoliths/cm ka) at 123-122 ka BP. The coccolithassemblage was dominated by two size-morphotypes of Gephyrocapsa alternating in dominanceunder different climatic conditions: Gephyrocapsa muellerae was more abundant in colder
periods, whereas "small Gephyrocapsa" dominated in the Eemian. Emiliania huxleyi,
Syracosphaera pulchra and Florisphaera profunda increased in the Eemian whereas Coccolithus
pelagicus and Helicosphaera carteri decreased. Small Gephyrocapsa together with Emiliania
huxleyi are associated with periods of higher productivity. The E. huxleyii(E. huxleyi +G.
muellerae) ratio is used as a proxy for paleoclimate changes in this region.
At 53 °N (core T90-2P), 8° to the north, G. muellerae dominated the calcareous
nannoplankton assemblage throughout the whole interval. During the Eemian its relative
abundance decreased down to 40 % at the Eemian maximum (125 ka BP). At this site small
Gephyrocapsa was always present but never dominated the assemblage.
The pelagic sedimentary record of Termination II in the northeast Atlantic includes a 515 cm thick layer enriched in ice-rafted material, a so called Heinrich layer. In contrast to
Termination I, where such a Heinrich layer (Hl) is associated with the first meltwater pulse of
the deglaciation, the Heinrich event ofTermination 11 (H11) occurred during the second stage of
deglaciation (129.4-127.1 kaBP).It is characterized by accumulation ofice-rafted debris andlow coccolithophore diversity. The coincident drop in coccolith accumulation rate could be
explained either by changes in primary productivity due to reduction in salinity and light, or by
dilution by ice-rafted material. It further could be an artifact resulting from low dating precisionand incorrect thickness definition of the Heinrich layer. Five models are applied for thedeposition of the Heinrich layer with changing thickness (3 cm) and duration (1000, 500 and 250
years). These scenarios result in a lowered, constant or even slightly increased primary
productivity during this event.

High ResolutionBbiostratigraphy in the North Sea Chalk
Fabio Lottaroli and Donata Catrullo
AGIP. PO Box 12096- 20120 MILANO, ITALY. E-mail: fabio.lottaroli@agip.it

INTRODUCTION
Chalk cored sections of twelve selected wells of the Greater Ekofisk area (Central North
Sea ) were studied for biostratigraphical purposes by means of calcareous nannofossils. The
studied interval is developed in the uppermost Tor Formation (Maastrichtian) and Ekofisk
Formation (Danian). Wells from Edda, Tor, Ekofisk and Eldfisk have been studied, among
others. The high resolution biostratigraphy, together with the results of sedimentologicaldescription, was intended to form the base for a sequence statigraphic framework suitable for thisarea.
MATERIALS AND METHODS
Wells 2/5-7,2/4-8,2/5-2,2/5-3, 2/4b-19A, 217-4,217-3 and 2/8-2 were first studied ingreat details and the biostratigraphic approach was, as far as possible, quantitative. Eighty-fourcores for a total length of 780 m have been studied in this first phase. The cores were sampled forbiostratigraphy simultaneously with the visual core description. Therefore, samples (tot. 450) arerepresentative of facies variations and stratigraphic development and their frequency is strictly
related to facies interpretation. Anyway, the samples spacing rarely exceed 1 meter in Ekofisk
Formation; only in the coarse reworked facies of Tor Formation the samples are more scattered.
The biostratigraphic analyses were performed on smear-slides with an optical microscope(x1250). Three hundred specimens of calcareous nannofossils were counted in each sample andfor the Danian sediments an additional count (50 specimens) was performed in order to estimate
the evolutional degree of the Cruciplacolithus-Chiasmolithus assemblage (Van Haeck & Prins,
1987). The Maastrichtian sediments ofTor Formation were often so depleted of calcareous
nannofossils to prevent from reaching 300 specimens counted. Available published biozonations
developed in this specific area were chosen as reference both for the Cretaceous (Mortimer,
1987) and Danian. For the latter the maximum detail was obtained combining the biozonations ofPerch Nielsen (1979) and Van Haeck & Prins (1987). In a second phase Fifty-two Core samples
from wells 2/1-1, 2/4-7, 2/5-1 and 2/5-5 were studied to implement the regional biostratigraphic
framework arising from phase I.
RESULTS
Biostratigraphy provided an extremely detailed subdivision mainly for the Daniansediments, where rapid evolution and appearances of new marker species make refined
subdivision possible. So a good correlative framework between studied wells have beenobtained, and even minor hiatuses were pointed out and consistently recorded at the regional
scale. Moreover biostratigraphic analysis supported facies characterization pointing out reworked
intervals. As already outlined for Chalk Group in this area, also for the studied interval thehistory of sedimentation is a complex interplay of autochthonous and allochthonous deposition,
where redeposition represents the norm rather than the exception. Cretaceous reworked
assemblages mixed with in situ Danian was rarely found. More frequently, intervals containing
only Maastrichtian nannoflora were found embedded in the Danian sequence (2/5-7). Often, due

to the good biostratigraphic resolution, lower Danian interval have been recognized reworked
into younger Danian sediments (2/4-B19a).- The cored interval of2/5-7 well has been referred
to lowermost Danian (D 1) based on the nannofloral content of two centimetric clay-rich layers.
The rest of the core, also the intervals identified as "pelagic chalk", contains only late
Maastrichtian nannoflora. The presence of the KIT boundary at the base of this core iscorroborated by the occurrence of Prediscosphaera stoveri acme (Posphical & Wise, 1990). - A
hiatus or a very condensed section between sediments referred to D 1 and upper D4 Biozones was
detected in almost all the wells corresponding to a hard ground level (2/4-8) or to a clay-richinterval. - Hard ground were found to correspond to hiatuses also at higher stratigraphic levels(2/4-8).- Also the time span corresponding to D5-D9 Biozones seems poorly represented insome wells, even if, the lithological expression of this event is less clear.
REFERENCES
HECK.,S. VAN & PRINS,B.(l987): A refmed nannoplankton zonation for the Danian of the North Sea. Abh.Geol.B.-A.,39:279-284 MORTIMER,C.P.(1987): Upper Cretaceous calcareous nannofossil
biostratigraphy of the southern Norwegian and Danish North Sea area.- Abh. Geol.B.-A. ,3 9: 143-17 5
PERCH NIELSEN, K. (1979): Calcareous nannofossil zonation at the Cretaceousffertiary boundary in Denmark.
-in Birkelund,T.& Bromley, R.G.(eds.): Cretaceous-Tertiary boundary events symposium, 1:115-135
PERCH NIELSEN, K. (1985): Mesozoic and Cenozoic Calcareous nannofossil; In Plannkton Stratigraphy, Bolli
H.M., Saunders J.B., Perch-Nielsen K. ed. Cambridge University Press.
POSPICHAL,J.J.& WISE,S.W.(1990): Calcareous nannofossils across the KIT boundary, ODP hole 690C, Maudrise, Weddell sea.- Proceedings ofODP, V.113 : 515-532.

Onset of "Helminthoid Flysch" Sedimentation in the Western Tethys: Evidence from
Antola Fm. (Northern Apennines, Italy)
Michele Marroni, Luca Pandolfi and Nicola Perj)]j
Dipartimento di Scienze della Terra, Universita degli Studi di PISA, ITALIA
E-mail: marroni@dst.unipi.it; perilli@dst.unipi.it

In the Northern Apennines (Italy), spectacular, thick and widespread "Helminthoid
Flysch" deposits crop out. These successions, consisting of fine-grained nannofossil-rich
calcareous turbidites, sedimented in the Western Tethys Domain during the Late CretaceousEarly Tertiary intraoceanic subduction and the following Europe-Adria collision. Similar
deposits characterized by helminthoidea trace fossils crop out in French and Italian Maritime
Alps, Swiss Pre-Alps, Central Switzerland, Bavarian Alps and Wienerwald of Austria. In the
Northern Apennines, the "Helminthoid Flysch" represents the huge part of different tectonic
units such as Antola, Cassio and Caio Units.
This work deals with calcareous nannofossils biostratigraphy of the lower portion of
Antola Fm. cropping out northeast ofGenova (Italy). The onset age ofHelminthoid Flysch
sedimentation represents an important starting-point to enlighten the tectono-sedimentaryevolution of the Ligure-Piemontese Domain.
The Antola Unit includes a "basal complex" (Montoggio Shale) and the overlying Antola
Fm. Made up of a 2000m thick calcareous turbidite sequence, the Antola Fm. is characterized bymedium to thick calcareous beds and minor siliciclastic medium to thin beds. The
sedimentological features of a calcareous turbidite sequence and the presence of thin hemipelagic
CaC03-free claystones indicate a basin plain environment located below the local CCD.
The Helminthoid Flysch dating is problematic because of both the intense reworking ofthese deposits and the impoverishing of the calcareous nannofossil assemblages due to thetectonic stress, which affected the lower part of the tectonic unit.
In total, 110 samples were investigated: 29 of them were collected from the basal portionof the Antola Fm. and 91 from the 400 m thick overlying succession. The first group ischaracterized by poor to medium preserved calcareous nannofossil assemblages, with totalabundance ranging from few to common and the number of species ranging from 10 to 20. The
second group provide more abundant, diversified and the best preserved assemblages with anumber of species ranging from 20 and 30.
The nannofloras are dominated by Watznaueria barnesae and Micula decussata, together
with Ca/culites obscurus, Cribrosphaerella erhenbergii, Lucianorhabdus cayeuxii, Micula
staurophora and Prediscosphaerea cretacea. Other frequent taxa are Ceratholitoides aculeus,
Cretarhabdus crenulatus, Eiffellithus turriseiffelii and Microrhabdulus decoratus. The
nannofossil assemblages from the lowermost calcareous turbidites of the Anto la Fm. arecharacterized by the presence of Ceratholitoides aculeus, Quadrum gothicum, Quadrum trifidum
and Reinhardtites levis and are referable to the Quadrum trifidum Zone (late Campanian-early
Maastrichtian).

Lower Jurassic Integrated Biostratigraphy Based on Calcareous Nannofossils andDinoflagellateCcysts in the Tethyan Realm
Emanuela Mattjo)j & Raffaella Bucefalo Palliani
Dipartimento di Scienze della Terra, Universita di Perugia, P.za Universita, PERUGIA- ITALIA

Well preserved calcareous nannofossil and dinoflagellate cyst assemblages were collectedfrom numerous successions outcropping in Tethyan localities. The reference area for this study iscentral Italy, where continuous sections well dated by ammonites are particularly suitable for an
integrated biostratigraphical approach. Comparisons were carried out with the phytoplanktonic
assemblages from Greece, southern France, Hungary, Portugal and southern Germany. This
study is focused on the Lower Jurassic, period characterized by numerous global
palaeoecological and palaeogegraphical events (speciations, transgressions, anoxia, etc.). In theLower Jurassic marine phytoplankton producing fossilizable remains is mainly represented bycalcareous nannoplankton and dinoflagellates. During this time interval, both groups experienced
an evolutive radiation and colonized oceans and epicontinental seas.
The integration of selected calcareous nannofossil and dinoflagellate cyst events
produced a very detailed biostratigraphical framework. This may represent an importantparachronology to ammonite zonation. The integration of the two phytoplanktonic groups
enables sediments to be dated even when lithologies unfavorable to the preservation of one fossil
group are present. The light diachroneity between the Early Jurassic radiation of nannoplankton
and dinoflagellates ensures that this approach has a good biostratigraphic potential. The
biostratigraphic framework obtained in the present work yielded greater detail than that provided
by ammonites and it is generally independent from the sedimentary facies.

The Eustatic andCiimatic-orbital Sinature on Phytoplankton and Geochemistry:
Examples from the Early Toarcian in Central Italy
E Mattioli\ R. Bucefalo Palliani\ S. Cirilli S. 1 and B. Pittet 2
1

2

Dipartimento di Scienze della Terra, Universita di Perugia, P.za Universita, 06100 PERUGIA, ITALIA.
Universite de Fribourg, Institut de Geologie et Paleontologie, Perolloes, CH-1700 FRIBOURG, SWITZERLAND

In central Italy (Umbria and southern Tuscany) the Early Toarcian consists ofmonotonous mixed carbonate-siliciclastic lithologies, rich in organic matter and with a scarcity
of sedimentary structures. Six profiles were investigated in detail with a multidisciplinary
approach. Quantitative and multifactorial analyses were applied to calcareous nannofossils,
dinoflagellate cysts, organic constituents of palynofacies, and geochemical parameters (TOC, HI,
OI, CaC03). The aim ofthis research is to emphasize the potential ofphytoplanktonic andgeochemical parameters as palaeoenvironmental indexes. Factor analysis evidences the existenceof three main factors controlling the phytoplankton distribution, which are related to climaticeustatic fluctuations.
•

•
•
•
•

The calcareous dinoflagellate Schizosphaerella spp. is present everywhere in the studied
lithotypes, its abundance is controlled by variations of the other groups, but blooms occur
when carbonate rich layers are deposited;
Biscutaceae and Lotharingius spp. are generally abundant in highly diversified
assemblages; they dominate under good trophic conditions;Crepidolithaceae probably represent the deepest specimens living in the water column oroff-shore taxa. Their abundance is probably dependent on the nutricline depth;
Calyculus spp. is commonly abundant during high sea-level phases;
Mitrolithus spp. dominates during maximum-flooding to high-stand conditions, when thetrophic level is low.

The whole set of data reveals a succession of palaeoenvironmental and palaeoecologicalmodifications in the sedimentary basin during the global Lower Toarcian transgression linked totwo orders of eustatic and/or climatic cyclicity
3rd order cyclicity
Transgressive trend: The sea level rise created new available niches, promoting aphytoplanktonic speciation. The phytoplankton bloom contributed to the organic matteraccumulation. The successive anaerobic conditions at the sea bottom were favored by theinterplay of the sea level rise and sedimentary starvation. The stratified water column prevented
nutrient recycling and phytoplankton reached climax conditions in the relatively oligotrophic
surface waters. The decrease ofbasinward-transported carbonate mud is related to the flooding of
the adjacent carbonate platforms and the scarce CaC03 is mainly produced by Schizosphaerella
spp. At the end of the transgressive trend the maximum palaeoenvironmental distality,
sedimentary starvation and TOC values are related to the maximum flooding event. The deeper
and/or distal nannoplankton taxa prevailed concomitant with this event. The dinoflagellate cysts
temporarily disappeared and the Tasmanites became the dominant organic-walled phytoplankton.

Regressive trend: The sea level fall at end of the Early Toarcian gave rise to a more efficientwater circulation, producing a reoxygenation at the sea bottom, a better nutrient recycling and a
new phytoplanktonic bloom. Export of carbonate mud produced on the platform increased again.
4th/5th order cyclicity
Time series evidenced that the fluctuations in the phytoplankton and geochemical indexes arecontrolled by orbital parameters (eccentricity, obliquity and precession cycles). These cyclic
signals are interpreted as a result of climatic and oceanographic changes inducing variations inthe surface fertility, carbonate productivity and sea bottom oxygenation. A climatic cycle may beinferred to explain the differences in the geochemical signature and phytoplankton distribution
with respect to carbonate production. When carbonate-poorer layers were deposited, a warmer
and more humid climate could have produced water stratification and organic matteraccumulation and preservation. A more efficient water circulation and vertical mixing,
suggesting higher seasonality, could have determined the deposition of carbonate-richer
sediments.

Cretaceous Nannofossil Biostraigraphy of Lithuania
Romualda Mertiniene
Institute of Geology, Sevcenkos 13, Vilnius, LT 2600, LITHUANIA

The analysis ofnannofossils from the Cretaceous of Lithuania have allowed us todistinguish the nannoplankton zones. The Lower Cretaceous consists of non-carbonaceous sandsand siltstones. Nannoplankton are not found there. The Upper Cretaceous is represented byvarious carbonaceous rocks. Nannoplankton found in these deposits were investigated. Several
nannoplankton zones, distinguished by the author in 1993 are determined more exactly.
The lower boundary of each zone is marked by the first appearance of the index-species.
Sizes of individual zones are various. The determination of the nannoplankton zones is based
upon the existing foraminferal zones.
Nannoplankton in the Lower-Middle Cenomanian are rare and badly preserved. A
Nannoplankton zone is not distinguished there.
Ten nannoplankton zones were distinguished in the remaining Upper Cretaceous
deposits:
...
...
...
...
...
...
...
...
...

Upper Cenomanian-the bottom of Lower Turonian- zone Gartnerago obliquumMicrohabdulus decoratus.
Most of the Lower Turonian - zone Quadrum pyramidum.
Upper Toronian- most of Upper Coniacian- zone Lucianorhabdus maleformis.
Top of the Upper Coniacian- the lower half of Lower Santonian- zone Micula
staurophora.
The upper part of Lower Santonian- Uppper santonian- zone Lucianorhabdus cayeuxi.
The most of Lower Campanian - zone Briosonia parea.
Top of the Lower Campanian- the lower part of Upper Campanian- zone Ceratoltoides
aculeus.
Top of the Upper Campanian-the Lower Maastrichtian- zone Quadrum trifidum.
Top of Lower Maastcichtian- the lower part of Upper Maastrichtian =zone Lithraphidites
quadratus
Upper part of Upper Maastrcichtian- zone Nephroltihus frequens

Statistical Analysis of Sequential Abundances Data: Paleo-Ecological Evidences from theUpper Eocene Massignano Section (Central Italy)
Sjmonetta Monechi 1, Antonella Buccianti 1 and Silvia Gardin 2
1

Dipartimento di Scienze della Terra, Via La Pira 4, 1-50121 FIRENZE, ITALY.
E-mail: monechi@cesitl .unifi.it
2
CNRS URA 17 61 Departement de Geologie Sedimentaire Laboratoire de Stratigraphie,
Universite Pierre et Marie Curie 4, Place Jussieu F75252 PARJS Cedex 05, FRANCE

The analysis of sequential data has come to play a prominent role in a wide spectrum ofsciences. The investigation oftime series of fossil records has pointed out the possible signatureof periodicity in mass extinctions probably related to external influences such has meteorite
impacts (Sole' et al. 1997). Quantitative evaluation of data that can be considered as time (orspatial) series can be performed by using a large number of methods (e.g. Box and Jenkins,
1970; Kendall and Ord, 1990). In this work we attempt to analyze and interpret the changes ofabundances of different species whose behavior can be related to climatic changes by usingclassical and geostatistical methodologies (Oliver et al., 1997). The aim is to identify
meaningful patterns in the vertical distributions of each sequence of abundances data
(autocorrelation), to perform cross-correlations among different sequences and finally to detect
the presence of relationships with external factors as meteorite impacts. Since .strong evidence
for a major early late Eocene impact was found in a level of the Massignano section (stratotypeof the Eocene/Oligocene boundary) the statistical analysis has been applied to data collected·from it.
A problem in the analysis of the abundances data arises if the values are expressed inpercentage (or relative data). As demonstrated by Aitchchison (1986), the analysis ofcompositional (closed) data requires the transformation of the original quantitatives in order toavoid the problem of the induced correlations. Thus, in this study the statistical analysis isapplied by considering the problem of compositional data. Our efforts have been useful to pointout and interpret: 1) the organization of the data inside each vertical sequences; 2) relationships
between the different vertical sequences; 3) detection of grouping of variables (discoasters,~olococcoliths, cold water taxa) that show a similar behavior related to the same climatic and/or
paleoecological and paleoenvironmental features; 4) the link between changes in the abundances
data and the occurrence ofbiotite.

REFERENCES

AITCHSION J., 1986. The statistical analysis of compositional data: Chapman and Hall 416 p.
Box G.E.P., JENKINS G.M., !970: Time series analysis, forecasting and control. Holden-Day, Oakland, CA, 553 p.
KENDALLM. ORD J.K., 1990.Time series: Edward A. Kent, 296 p.
0LIVERM.A., WEBSTERR., EDWARDS K.J. WHITIINGTON G., 1997. Multivariate, autocorrelation and spectral
analyses of a pollen profile from Scotand and evidence of periodicity. Rew. Paleobotany and Palynology,
96, 121-144.
SOLE' R.V., MANRUBIA S.C., BENTON M., BAK P. Self-similarity of extinction statristics in the fossil record. nature.
338. 764-767.

/Calcareous Nannoplankton In The Cariaco Basin, Venezuela
Di Gianni C 1• and Nieves M 2
1

Laboratorio Geol6gico El Chaure, Corpoven S.A., Apart.4623, Puerto La Cruz,
Edo. Anzoategui, Venezuela,
E-mail: gesp3 8 @ccinet. corpoven.pdv .corn

2

LAMBERT, Bemard., Total Indonesie, Jalan Myniak, Balikpapan, Kalimantan Timur Indonesia.

In order to determine a referential environmental model, the horizontal and vertical
distribution of calcareous nannoplankton in the water column of the Unare-La Tortuga traverse
and its effect on the ocean floor sediments was investigated. For the study, water samples weretaken in 9 hidrographic stations at depths ranging from 0 to 200 m, as well as, 5 ocean floor
surface sediment samples corresponding to the continental shelf, the slope and the anoxic
Cariaco basin. In addition, a bathymetric registry of the traverse was recorded and thehydro graphic conditions of the water column were determined using parameters such astemperature, density, salinity, dissolved oxygen and chlorophyll content.
Around twenty species of nannoplankton were identified in the analyzed samples, which
could be grouped into the genera Gephyrocapsa, Emiliania and "Others" (with species from thegenera Florisphaera, Helicosphaera, Umbilicosphaera, etc.).
The largest concentration of cells in the water column (up to 4050 cell/liter) wereobtained at 50 m of depth and in the center of the basin, decreasing noticeably in the northdirection towards La T ortuga island. The predominance of Gephyrocapsa over Emiliania wasobserved along the entire traverse, especially in the coasts. Towards the center of the basin, thisrelation is reversed. At depths greater than 50 m, specimens from the "Others" group were moreabundant, with the greatest amount accounted by the Florisphaera genus.
The results from the analyzed sediment samples indicate the predominance of the genus
Gephyrocapsa. The sediments from the continental shelf sample show low diversity andabundance of nannoplankton, which increases considerably towards the center of the basin. In
addition to the diversity of phytoplankton, complete and well preserved coccosphaeras can beobserved at 1340 m, as well as, a great amount of pyrite and amorphous organic matter. The
presence of the Disco aster genus and the Calcidiscus macintyrei species in the sediments, extinct
in the Pliocene and early Pleistocene respectively, may indicate a low sedimentation rate or
reworked specimens at this northeastern region of Venezuela.

Nannoplankton, Cariaco, Quaternary, water-samples, sediments

Name : Nieves Maria DI GIANNI CANUDAS
Address: Laboratorio Geologico El Chaure, (Corpoven, S.A.) P.D.V. S.A.
PUERTO LA CRUZ, EDO. ANZOATEGUI, VENEZUELA
E-mail: gesp38@ccinet.corpoven.pdv.com
FAX: 58-81-606445
TEL: 58-81-606399

Seasonal Variation of Modern Coccolithophores in the
Subarctic Pacific Ocean and Bering Sea
H Okada, and K. Hagino
Department of Earth and Planetary Sciences, Graduate School of Science,
Hokkaido University, SAPPORO, 060-0810 JAPANE-mail: oka@cosmos.sci.hokudai.ac.jp; hagino@strati.sci.hokudai.ac.jp

Observation of more than 500 surface and subsurface filter samples collected from thesubarctic Pacific and Bering Sea revealed seasonal trends in coccolithophore flora. The samples
were collected by various scientific cruises in spring to autumn seasons (June- September) for
multiple years between 1964 and 1997. Seasonal variation of the flora within this sub arctic realm
was much more intense than was reported in the North Atlantic (Okada and Mclntyre, 1975). The
coccolithophore distribution was patchy, and many samples were barren or extremely scarce of
coccolithophores.
Approximately 70% of the studied samples were barren, and only 9 out of 96 samples,collected in four years, yielded more than 1000/L cells in the Bering Sea. Major components ofthe flora were Emiliania huxleyi and Coccolithus pelagicus with the former being far moreabundant in the densely populated samples. A moderate bloom of E. huxleyi (ea. 5 million!L
cells) was recorded for the first time from the Pacific sector. Calciopappus caudatus dominatedthe flora (70%) in some samples. Due to insufficient number of samples studied, a clear seasonal
trend was not observed, but the higher population density seems to occur during the middle tolate June in the Eering Sea. The data also indicates a higher population in shallow (1 0-50 m)
subsurface waters than in surface waters.
Seasonal variation in the standing crop was greater in the Subarctic Zone (north of ea. 45°N) compared to the northern Transitional Zone (ea. 40-45°N) in the Pacific. The generally low
standing crop(< 10,000/L cells) in June has jumped to levels two orders of magnitude higher
between late July and late September in the Subarctic Zone, whereas the seasonal difference in
the Transitional Zone stayed within one order of magnitude, with the summer population of ea.
100,000/L cells.
Similar to the Bering Sea flora, the Pacific Subarctic flora was dominated by E. huxleyi
and C. pelagicus. A sporadic occurrence of abundant C. caudatus was also common to both
floras. Nannoflora of the northern Transitional Zone showed high diversity with common toabundant occurrences of Syracosphaera spp., Calyptrolithophora spp. and Rhabdosphaera
clavigera. Standing crop was generally the highest in 25-50 m water depth, and the population
density was often two orders of magnitude higher than the surface level. Moreover, the floral
composition differed significantly between these water depths at some stations.
Multiple year studies of sediment trap samples have revealed significant annual variations
in carbonate flux in subarctic regions (ex. Takahashi et al., 1996). As a result of this study, it is
now obvious that the cause of the annual variation is a combined effect of regional (basin wide)and local variances. For an accurate estimation of total carbonate flux in the world subarctic
realm, multiple intrabasinal geographic coverage of sediment traps is needed. Also the significant
subsurface concentration of coccospheres in areas where the surface waters are devoid of thecells may require some adjustment for the interpretation of remote sensing data.

Miocene Calcareous Nannofossil Magnetobiostratigraphy and Biochronology
Alyssa M Peleo-Alampay

Scripps Institution of Oceanography, University of California, San Diego
La Jolla, CA 92093-0208 USA.
now at National Institute of Geological Sciences, University of the Philippines
Diliman, Quezon City, Philippines 1101. E-mail: ampa@nigs01.cs.upd.edu.ph.

Fifty three calcareous nannofossil events of the middle to upper Miocene are investigatedin eleven DSDP/ODP sites from the low to mid-latitude Atlantic, Pacific and Indian Oceans.
Nannofossil datums are calibrated with magnetostratigraphy at each site and numerical ages are
assigned based on the geomagnetic polarity time scale. This allows a comprehensive evaluationof the nannofossil datums in terms of their numerical ages and their consistency and reliability
for stratigraphic correlation on a global scale.
The following middle to late Miocene datums are shown to be the most reliable: the last
occurrence (LO) of Discoaster quinqueramus, the LO of Amaurolithus amplificus, the firstoccurrence (PO) of Amaurolithus amplificus, the LO of Reticulofenestra rotaria, the FO of
Reticulofenestra rotaria, the LO of Discoaster hamatus, the PO of Amaurolithus primus, theFO of Discoaster hamatus, the PO of Catinaster calyculus, the PO of Discoaster bellus group,
the FO of Catinaster coalitus, the LO of Coccolithus miopelagicus > 13=B5m, the LO of
Cyclicargolithus jloridanus, the LO of Triquetrorhabdulus serratus, and the LO of Calcidiscus
premacintyrei. Significantly different ages from those commonly used in the literature areshown for the following datums: the LO of Discoaster loeblichii, the PO of Discoaster
quinqueramus/D. berggrenii, the LO of Discoaster bollii, the LO of Discoaster hamatus, the FO
of Minylitha convallis, the FO of Discoaster hamatus, the LO of Discoaster kugleri, the FO of
Catinaster coalitus, the LO of Coccolithus miopelagicus and the FO of Discoaster kugleri.
Several datums (the PO of Minylitha convallis, the FO of Discoaster neohamatus, theLO of Catinaster coalitus and the PO of Discoaster bollii) show diachroneity across different
regions or oceans. Two new datums are proposed: the LO of Discoaster formosus in subchrons
C5r.2r/C5An.ln (11.3 Ma) and the LO of Helicosphaera rhomba in chron C5r (11.3 Ma).

Unusual Oligocene Braarudosphaera-rich Layers of the South Atlantic and
Their Paleoceanographic Implications
Alyssa M Peleo-Alampay
Scripps Institution of Oceanography, University of California, San Diego
La Jolla, CA 92093-0208 USA
now at National Institute of Geological Sciences, University of the Philippines
Diliman, Quezon City, Philippines 110. E-mail: ampa@nigsOl.cs.upd.edu.ph

The origin of the Oligocene Braarudosphaera layers over large ocean basins hasremained a mystery since the question was raised almost three decades ago by the Deep Sea
Drilling Project. Results from a detailed micropaleontologic study coupled with oxygen andisotope data from Sites 363 and 522 in the South Atlantic have shed some new light on thisquestion. The first quantitative Braarudosphaera abundance data collected in this study correlatewith oxygen isotope curves and suggest that Braarudosphaera preferred cold waters. Variationsin the relative abundance of sphenoliths (warm water taxa) and longer C. pelagicus placoliths
indicate colder water conditions during times of elevated Braarudosphaera deposition.
Upwelling and mid-ocean overturn of cold, nutrient-rich, low salinity water are inferred as
possible paleoceanographic mechanisms for the deposition of Braarudosphaera layers.

Early-Middle Toarcian Calcareous Nannofossils of San Andres and Camino Sections(Cuenca Vasco-cantabrica, Spain)
Nicola Perj]]jDipartimento di Scienze della Terra, PISA, ITALY. E-mail: perilli@dst.unipi.it

This study is focused on calcareous nannofossil biostratigaphy of lower and middle
Toarcian platform deposits cropping out in the western sector of the Cuenca Vasco-Cantabrica(northern Spain). The continuous and nicely exposed San Andres and Camino sections arelocated in the Reinosa area (Santander province of Cantabria Community).
The investigated successions span from Tenuicostatum to Variabilis Zones, and consist ofthin to mediumly bedded alternating marstones and limestones. These sediments contain nicely
preserved and continuous ammonite assemblages, which provide a refined biostratigraphic
framework.
This study is based on more than 150 closely-spaced samples, mainly collected frommarlstones and marly limestones. Semiquantitative analysis carried out with a light polarizing
microscope revealed rare to common and medium to poorly preserved nannofossil assemblages.
The samples from the lower portion of both sections yielded the most abundant, diversified andbest preserved assemblages.
Among the others, the following calcareous nannofossil events are easily detectable: LCO
of Mitrolithus }ansae, FO of Carinolithus superbus, FO of Discorhabdus striatus and LCO of
Lotharingius hauffii. The identified events are calibrated with the ammonite Zones, andcorrelated to the early-middle Toarcian biohorizons recognized in the Cordillera lberica.

Calcareous Nannofossil Biostratigraphy of Early and Middle Toarcian from the Cordillera
lberica and Cuenca Vasco-Cantabrica (Spain)
Nicola Perilli 1 and Antonio Gof
1

Dipartimento di Scienze della Terra, Universiti degli Studi di PISA, ITALY. E-mail: perillia@dst.unipi.it
2
Departamento de Paleontologia, Universidad Complutense, de MADRID, SPAIN

A calcareous nannofossil biostratigraphy was performed on lower and middle Toarcian
deposits from Spain. The investigated sections crop out in the central sector of the Cordillera
Iberica (Rambla del Salto and La Almunia De Doii.a Godina-Ricla sections) and in the western
sector of the Cuenca Vasco-Cantabrica (San Andres and Camino sections). The studied platform
deposits consist of thin to mediumly bedded altemance ofmarlstones and limestones. In bothareas, the sediments contain quite common and nicely preserved ammonite assemblages, whichallow to recognize and give a detailed definition of the Tenuicostatum, Serpentinus, Bifrons andV ariabilis Zones and their Subzones.
In these sections, more than 400 closely-spaced samples, mainly from marlstones andmarly limestones, were collected. Semiquantitative analysis performed with a light polarizing
microscope points out an excellent and continuous succession of nannofossil assemblages fromearly to middle Toarcian. The identified calcareous nannofossil events are calibrated to theammonite biostratigraphy, and compared to the early and middle Toarcian biohorizons
recognized in other Tethyan and Boreal areas.

Ceramic Nannopalaeontology
Patrick Sean Quinn

University of Sheffield, ENGLAND. E-mail: prp95psq@sheffield.ac.uk.

Nannofossils are a relatively common component of Bronze Age archaeological ceramics
from the Southern Aegean, but have been more or less ignored by ceramicists, perhaps due totheir extremely small size, which is beyond the resolution of most petrographic microscopes.
Nevertheless these minute calcareous inclusions have several advantages over the more
conspicuous micro fossils such as foraminifera and ostracodes as a means of characterizing,grouping and provenancing ceramics. The following paper outlines the methodology by which
calcareous nannoplankton can be studied in ceramics and discusses the many difficulties
involved in looking at microfossils from archaeological material, as well as presenting several
case studies from an ongoing research project at the University of Sheffield.

Sequence Biostratigraphy of a Shallow Marine Environment:
Campanian and Maastrichtian Sediments of South Carolina, U.S.A.
Jean M Self-Trail and Gregory S. Gohn
U.S. Geological Survey, Reston, Virginia 20192, U.S.A. E-mail: jstrail@usgs.gov

Calcareous nannofossil biozones are used with core and geophysical-log data to identify
and map subsurface Cretaceous depositional sequences in the South Carolina Coastal Plain. The
processes controlling taxon ranges and depositional-sequence boundaries in marine sediments are
not independent; calcareous nannofossil zonal boundaries occur at sequence boundaries whereshelf sands are the basal deposits and above sequence boundaries where nearshore basal deposits
are preserved. The Coachman Formation (oldest), Bladen Formation, and overlying Donoho
Creek Formation (youngest) consist of six Campanian depositional sequences. Sediments near
the base of the oldest depositional sequence contain the first appearance of Ceratolithoides
aculeus, and therefore the two older sequences are assigned to calcareous nannofossil Zones CC
19 and CC 20. The base of the third-oldest sequence is approximated by the first appearance ofQuadrum sissinghii, and sediments at the top of the Donoho Creek record the last appearances ofReinhardtites anthophorus and Reinhardtites levis. Accordingly, the younger four sequences are
assigned to calcareous nannofossil Zones CC 21 and CC 22. Ofthese four sequences, the older
two are separated from the younger two by an unconformity marked by the first appearance ofQuadrum trifidum. In sequences where basal, nearshore, bedded-sand deposits are preserved
above the basal unconformity, calcareous nannofossil zonal boundaries tend to occur above, notat, the sequence boundary in overlying deeper water muds (maximum flooding deposits).
Nannofossil assemblages are more diverse in the deep water muds, whereas
holococcoliths tend to dominate the nannofloras in the nearshore sands. In contrast, calcareous
nannofossil zonal boundaries tend to occur at sequence boundaries where basal homogeneousquartz-glauconite shelf sands overlie the unconformity. The top ofthe Donoho Creek Formationis truncated by a major unconformity that encompasses the Campanian-Maastrichtian boundary(Zones CC 23 and CC 24 are absent) and is traceable throughout the South Carolina Coastal
Plain, using both calcareous nannofossil biostratigraphy and lithologic data from cores andgeophysical logs. Division ofthe Maastrichtian Peedee Formation into two mappable sequences
is facilitated by the coincidence of the first appearance of Lithraphidites quadratus with anextensive subsurface cemented zone (unconformity) that is present in the northeastern part of theSouth Carolina Coastal Plain. The Campanian and Maastrichtian depositional sequences andtheir corresponding calcareous nannofossil biozones have been traced across South Carolina andinto neighboring states. Observed patterns of Late Cretaceous deposition and erosion tend to varyon a broadly regional basis, thereby facilitating regional analysis.

Biostratigraphy of the Genus Scyphosphaera
William G. Siesser
USA. E-mail: siesser@ctrvax.vanderbilt.edu

Scyphosphaerids are frequently found in low-latitude Miocene-Pliocene sediments. The
genus first evolved in the early Eocene (Zone NP12), but abundance and diversity remained low
until middle Miocene Zones NN5-NN6, when global radiation began. More new species (24)evolved during the Miocene NN5-NN6 and NN9 zonal intervals than at any other time. The
abundance acme for the genus is the late Miocene (NN9)-late Pliocene (NN15) interval.
Diversity peaked in early Pliocene Zones NN12 and NN13, with 31 extant species. Abundanceand diversity began to decline markedly in the late Pliocene, with a first wave of extinctions
occurring in late Pliocene Zone NN16B. A second wave of extinctions began in late Pleistocne
Zone NN20. Only two scyphosphaerid species live in the oceans today.

Palaeobiogeography of Early Cretaceous Calcareous Nannoplankton
Christianne Street and Paul R. Bown

Department of Geological Sciences, University College London, Gower Street, London, WCIE 6BT, UK
E-mail: c.street@ucl.ac.uk; p.bown@ucl.ac.uk

Distinct palaeobiogeographic distributions have been postulated for numerous Early
Cretaceous calcareous nannofossil taxa, although these are based largely on qualitative
observations. Species are commonly labeled 'boreal' or 'tethyan', and more recently bipolar
distributions have been observed, as well as taxa with restricted southern high-latitude, i.e.
austral, distributions. In this study we have attempted to quantify biogeographic differentiation
through the Early Cretaceous. A transect of sites, mainly from the Atlantic Ocean, provides a
North-South sample set. Additional samples sites from the Southern Hemisphere have beenstudied for comparison. Quantitative assemblage data have been gathered from each site forseven time-slices (Berriasian to Aptian), determined by well-established nannofossil datums. The
data have been analyzed in a number of different ways, including 1) latitudinal relative
abundance plots, which allow comparison with extant data sets, e.g. Mclntyre and Be, 1967, andOkada and Honjo, 1973; and 2) principal components analysis and other statistical techniques,
providing a more objective measure ofbiogeographic differentiation.

REFERENCES
MclNTYRE, A. AND B:E, A. W. H. (1967). Modem coccolithophorids of the Atlantic Ocean. 1. Placoliths and Cyrtoliths.
Deep Sea Research, 14: 561-597.
OKADA, H. AND HONJO, S. (1973). The distribution of oceanic coccolithophorids in the Pacific. Deep Sea Research, 20:355-374.

Summary of the Nannofossil Gulf Coast Equivalency Project
Michael J Styzen and Terri Dunn
Shell Offshore Inc., Room: OSS-3202, P.O. Box 61933, New Orleans LA 70161
E-mail: rnstyzen@shellus.com. Phone: (504) 728-4308

The Gulf Coast Equivalency Project is an ongoing project authorized by GCSSEPM. The
goal ofthe project is to produce a publication reconciling all Gulf Coast biostratigraphic
zonations. Most industry and academic biostratigraphers working this region have attended our
first four meetings and/or participated through our list server. We generally focus on a
specific lineage or family/genus grouping and discuss our various interpretations. We havediscussed the Discoaster quinqueramus!Discoaster berggrenii lineage in detail. Mike Styzen,
the nannofossil coordinator, has sketched all of the lineage members used as biostratigraphic
markers by all participants and noted the terminology each uses for these morphotypes.
The official focus of the project is the Oligocene to Recent section. The nanno groupagreed to use Mike Styzen's published chart, Late Cenozoic Chronostratigraphy of the Gulf of
Mexico, as a starting template for stratigraphic discussion. We have discussed definitions andstratigraphic placement of the Oligocene-Recent marker species of many genera. These include
Helicosphaera, Gephyrocapsa, Pseudoemiliania, Reticulofenestra, Dictyococcites, andSphenolithus. In addition to the D. quinqueramus lineage, most other biostratigraphically useful
Neogene Discoasters have been discussed. We have covered Cyclicargolithus to a lesser extent.
Most recently we have begun compiling original definitions of marker species and adding
the modifications of these definitions that we use in the Gulf Coast. Mitch Covington has
established a list server and he is also responsible for the database compilation. Ralph Solomon
has agreed to make photographs from his web site available for use in the project. Our
publication will include data compilation and photographs of marker and other significant
species. The format of this publication has not yet been decided.
In addition to our Oligocene-Recent project, we have recognized that the industry willencounter Cretaceous section in future Eastern Gulf and in the " Ultra Deep Play " in Gulf of
Mexico exploration. In November 1997, Professor David Watkins from the University of
Nebraska presented a week long workshop at Shell in New Orleans for industry biostratigraphersand coordinators. As the scope of exploration in the Gulf of Mexico expands to include theCretaceous, it is likely that we will expand the scope of our equivalency project to include
discussion of Cretaceous taxa.

Evidence of the Braarudosphaera-rich Sediments in the Turonian of the Bohemian
Cretaceous Basin, Czech Republic
Lilian Sva.benjcka
Czech Geological Survey, 118 21 PRAGUE, CZECH REPUBLIC. E-mail: svab@cgu.cz

Nannofossil assemblages enriched in Braarudosphaera bigelowii were observed in theTuronian epicontinental marine sediments of the Bohemian Cretaceous Basin in the Upohlavy
quarry, NW part of the Czech Republic. Calcareous mudstones exposed at the bottom of thesection yield rich and well preserved nannofossils with Lithastrinus moratus and Marthasterites
furcatus giving evidence for the Late Turonian, CC 13 Zone sensu Burnett (1996). Specimens of
B. bigelowii were not observed there.
Above, B. bigelowii appears abruptly at the base of a rhythmically bedded succession ofcarbonates (7.5 m in thickness- see Eech et al., 1996). Its relative abundance fluctuates between
1% and 5%. At the same horizon, character of nannofossils is distinctly changed. Assemblages
with reduced species diversity contained also Kamptnerius magnificus and Lucianorhabdus
maleformis in higher quantities. In contrast, Marthasterites furcatus, Lithastrinus moratus and"fragile" nannofossils, such as representatives of the family Stephanolithiaceae and related
genera disappear.
According to Uli~my (in Eech et al., 1996), the underlying mudstones represent
transgressive systems tract. The basal surface of the carbonate succession is interpreted as the
maximum flooding surface. The limestone succession can be regarded as a condensed section at
the base of a highstand systems tract. The upward decrease in CaC03 content across the
carbonate succession is explained to result from progressive dilution of pelagic component by
fine-grained terrigenous material, during deceleration of sea-level rise or stillstand in sea level.
The Braarudosphaera enrichment and the reduced diversity in nannofossil assemblages wellreflect this change in the paleoenvironmental conditions. The input of terrigenous material
probably triggered the abrupt Braarudosphaera bloom.
Both species M furcatus and L. moratus manifest their inconvenience to be usefulmarkers for precise biostratigraphic conclusion. It appears that their presence is strongly
influenced by litho logical character of sediments.

REFERENCES:
Bumett J.A.(l996): Nannofossils and Upper Cretaceous (sub-)stage boundaries- state of the art.- Journal of
Nannoplankton Research, 18, 1, 23-32. Hodonin.
Cech S., Hradecka L., Laurin J., Staffen Z., Svabenicka L. & Ulicny D. (1996): Locality 3: Upohlavy quarry.
Record of the Late Turonian sea-level oscillations and synsedimentary tectonic activity.- Fifth
International Cretaceous Symposium and Second Workshop on Inocerarnids, Field Trip Bl, 32/42.
Freiberg.

Modern Nannoflora from Off the Coast ofWestern Australia
Kyoma Takabasbi

Earth and planetary material sciences,
Graduate School of Science, Hokkaido University
tel:+81-11-716-2111ex.3519 fax:+81-11-746-0394
kyoma@cosmos.sci.hokudai.ac.jp
URL:http://strati.sci.hokudai.ac.jp/members/kyoma!index.htm

Distribution of modem calcareous nannoplankton was studied off the coast of western
Australia by analyzing 191 filter samples. These samples were collected from 0-200 meter water
depth at 33 stations during a scientific cruise ofRIV Franklin (CSIRO Australia) on 21 Feb.- 6
Mar. 1996.
A total of 95 taxa was observed by SEM observation of 118 samples in which
nannoplankton are common, and the presence ofthe upper and lower photic flora was evident ashave been documented in previous studies.
Association characteristics of the fourteen major taxa were analyzed and five groups wereidentified. These are, Group A: U irregularis abundant and no lower photic taxa existed; being
common in shallower samples oflow latitude area. Group B: abundant G. oceanica coexistingwith lower photic taxa and having characteristic distribution pattern. Group C 1: common
association of D. tubifera, R. clavigena stylifera and U tenuis without any lower photic taxa;
occurring in shallower depth of the higher latitude. Group C2: cooccurrence of E. huxleyi, G.
ericsonii, Syracosphaera spp., Holococcolithophores and U hulburtiana with some lower photic
taxa being common in shallower depth of the higher latitude. Group D: association of F.
profunda, 0. fragilis cavum, G. jlabellatus and A. oryza; its common occurrence limited indeeper water.

In the upper photic community, the relative abundance of AJ(A+C1 +C2) had clear
positive and negative correlations with temperature and salinity, respectively. In the lower photic
community, the value D/(D+C2) stays in lower level as long as the three nutrients, phosphate,nitrate and silicate, are in lower concentration. The value, however, becomes variable with somehigh points in samples with higher nutrient levels. Meanwhile the occurrence of Group B had nocorrelation with oceanographic environmental parameters including these three nutrients.

Late Quarternary Nannofossil Assemblages in the Transitional Northwestern
Pacific Ocean
Yujcbjro Tanak:aGeological Survey of Japane-mail: yuichiro@gsj .go.jp

Coccolith assemblages from two core collected in the Shatsky Rise (32°19.8'N,
157°5l.O'E, depth of2612 m) and the Hess Rise (34°ll.7'N, 179°15.4'E, depth of2664 m) haveprovided information on characteristics of the water masses. Two core sites are located on the
Kuroshio front region from the boundary between the subtropical and the transitional water
masses.
In two cores coccolith shows the glacial and interglacial cyclicity with major changes inassemblages and abundances. The coccolith assemblages during the last 200 kyr are dominatedby small placoliths (Emiliana huxleyi and Gephyrocapsa spp.) and G. muellerae. The reversal in
dominance between small Gephyrocapsa and E. huxleyi was identified in the isotope stage 5. E.
huxleyi shows a regular increase, whereas small Gephyrocapsa radical decreases in abundance.
G. muellerae and Calsidiscus leptoporus show higher fluxes in the north of the Kuroshio front
based on time series sediment traps around Hess Rise (Tanaka, 1995). Florisphaera profunda isgenerally abundant in low latitude region within the lower photic zone from 10° C to 28° C(Okada and Mclntyre, 1979). In the sediment traps around Hess Rise, this species occurs only atlatitudes lower than 35° N. Reversely, Coccolithus pelagicus occurs at latitudes higher than 37.5°
N G. muellerae is dominant at the glacial stages 2, 4, 6, and C. leptoporus are abundant during
interglacial stages 1, 5, 7 at two cores. In the interglacial stage abundances of C. leptoporus arecomparable to modem values. F. profunda is also abundant in interglacial stages and occurs 2 to
8 % in abundance during glacial stages. In two core sites, therefore, suggest north-south
displacement of the transition zone water mass throughout the past 200 kyr, but the integrity of
the Kuroshio branch region has been maintained.

Paleobiology of the Pelagic Realm
Hans R Thierstein\ Jorg Bollmann\ Mara Cortes\ Ali Haidar 1, Heinz Hilbrecht\ Michael Knappertsbusch2,
David Lazarus3 , K. von Salis Perch-Nielsen 1, Cinzia Spencer-Cervato4'Geological Institute, ETH-Zentrum, CH-8092 ZURICH, SWITZERLAND.
E-mail: thierstein@erdw.ethz.ch, mara@erdw.ethz.ch
2Natural History Museum, Augustinergasse 2, CH-4001 Basel, Switzerland
3
Institut fur Palaontologie, Humbolt-Universitat, Invalidenstrasse 43, D-10115 Berlin, Germany
4
Department of Geological Sciences, University of Maine, Orono, ME 04469-5764, USA

Global change issues are successfully being tackled by analyses and models of thephysical and chemical processes occurring on various timescales in the Earth system. What havesystematic biology, functional ecology, and paleobiology to contribute to Earth System
Science? What are the issues, theories and approaches?
With the development of data bases and computer-aided morphometric methods, newopportunities arise for paleobiological analyses on ecological as well as evolutionary timescales. In the micropaleontology group at the ETH attempts are being made to link theinformation gained from analyses ofliving phytoplankton dynamics at the JGOFS time-series
stations at Bermuda and Hawaii to the geological record preserved in deep-sea sediments.
The example ofbiodiversity and its potential controls is used as a model to address somefundamental issues of ecology as well as evolution.
On ecological timescales, Ali Haidar and Mara Cortes have correlated the multi-annual
coccolithophore cell density variability throughout the photic zone with the variability ofvarious environmental parameters measured by JGOFS scientists. Their results suggest, thatbetween 45-89% of the cell density changes can be explained by abiotic processes (bottom-up
control) and the remainder possibly by biotic interactions (e.g. grazing, competition, infections,etc.)
On the longer evolutionary timescales, analyses oflongevity of major skeletonizedplankton groups using our Neptune microfossil data base, have revealed surprising results. The
average geological age of recent species in the four major plankton groups (coccolithophores,
diatoms, foraminifera, radiolaria) is between 13.4-23 Ma, i.e. much older than generally
assumed. If three long-term coccolithophore survivors (Braarudosphaera bigelowii,
Scapholithus fossilis, Coccolithus pelagicus) are excluded, the range narrows to 13.4-15.0 M a,which is surprisingly small, considering the vastly different life strategies of the four groups.
Numerous coccolith species show distinct morphological variability in the living
plankton, in Holocene sediment assemblages and in the older sediment records. To what extent
the observed patterns are phenotypic (environmental adaptations) and/or genotypic (geneticallydistinct) is still an open question. A combination of culture experiments ofmonoclonalcoccolithophores under various growth conditions and analyses of their molecular genetics may
provide answers.

Calcareous N annofossil Biostratigraphy of the Oligo-Miocene Mollassic Succession of
Korea Depression, Southeastern Albania
Kico Vathi and Xhevdet Islami
Instituti Gjeologjik i NaftesFier, ALBANIAThe Depression ofKorca represents the extension towards the north of the Mesohellenicbasin in the Albanian territory. The oligo-miocene succession is transgressive on the basement
composed of the ophiolites, cretaceous-eocene limestones and the flysch of the Krast-Cukalizone. In this series several formations of local value have been distinguished.
The Middle Oligocene is characterized by coarse deposits including conglomerates,
sandstones, biodetritic limestones and silts. Their shallow origin (delta-shelf) is also proven by
the presence of the macrofauna and the neritic fauna. The Late oligocene consists ofturbidites
showing a predominance of the massive sandstones and conglomerates. Successively, the samecharacter of the sedimentation continues in Aquatinian and the lower part of the Burdigalian.
The upper part of the Burdigalian and the Langhanian are marked by the bluish marls rich inplankton. The lacustrine plio-pleistocene deposits are transgressive and contain only rare
Ostracoda and Charophyta.
The calcareous nannofossil assemblages observed in the Mesohellanic basin are very
similar to those of the Ionian zone. The abundance depends on the marine environment and thesort of sediment. Thus, the Middle Oligocene assemblages are very poor and generally of small
size. Gradually, the depth increases and the associations become more abundant, reaching the
maximum in the upper part of the Burdigalian and Langhanian. At the top of the series, anunusual predominance of Braarudosphaera and Micrantolithus announces the filling up of thebasin.

In terms ofMartini (1971) biozonation, the mollasic deposits of the Korea Depression
include the interval ofNP 24-NN 5 zones. The absence of Triquetrorhabdulus carinatus andDiscoaster druggi makes it difficult to distinguish the Early Miocene zones, so other events havebeen used.

Multivariate Analysis of Calcareous Nannoplankton and Stable Isotopic Study in theUpper Campanian- Lower Maastrichtian of the Campos Basin (SE Brazil)
lJiiz Carlos Veiga de Oliveira\ Rene Rodrigues\ Valesca Brasil Lemos2 , Ricardo Ayup-Zouain2, andIvanise Maria Wolff
1

PETROBRAS/CENPES/DIVEX/SEBIPE, Pd. 20, Cid. Universitiria, Quadra 7, 21949-900, RIO de JANEIRO,
RJ, BRAZIL. E-rnail: lcveiga@cenpes.petrobras.com.br.
2
Instituto de Geociencias!UFRGS, Campus Vale, Av. Bento Gon~alves 9500, 91509-900,
P. ALEGRE, RS, BRAZIL

Multivariate analysis was applied to nannofossils from 18 meter core drilled within an
upper Campanian- lower Maastrichtian section composed ofhemipelagic shales and marls.
Identified biozones included CC-23a, CC-22b and CC-21 after the zonal scheme ofSissingh(1977). A hiatus is suggested by the absence of zone CC-22a. According to biostratigraphic
correlations, absolute age estimates (Harland et al., 1989) and relative sea-level curves (Haq etal., 1987), the bottom ofthe cored section was deposited approximately at 76.5 M.a, and the top
at 73.8 M.a ago. The hiatus represents an erosional I non depositional time of about 1 M.a (75.774.7 M.a).
Multiple regression helped to determine the best counting method. Nineteen nannofossil
groups have been quantified, up to a cutoff of 200 specimens per sample. Fifty-seven samples
with 30 cm spacing have been analyzed. Watznaueria barnesae and Micula decussata dominate
the fossil assemblage and show inverse abundance in relation to each other.
Q-mode factor analysis (57 samples, 19 variables) shows that two factors explain 99.2%of the total variance in the microfossil assemblage. The first factor represents 83.6% of the total
variance, and the second factor only 15.6%. The first is associated with Watznaueria barnesae,
Cribrosphaerella ehrenbergii and Stradneria crenulata, and probably represents the original
nannoplankton population. The second factor is associated with Micula decussata, and isinterpreted to reflect nannofossil dissolution. Both factors were used to develop a depth-related
dissolution curve for nannofossils, which emulates a 4th to 5th order sea-level curve.
The interval corresponding to biozone CC-21 shows the highest dissolution rates andgreat amplitude oscillations in the oxygen isotope curve. The latter suggests that diagenesis
affected the oxygen cycle, but not the carbon cycle. The top of the studied interval corresponds toa sea-level fall responsible for the hiatus, which is well marked in the oxygen isotope curve.
The phase of relative lowstand and reduced dissolution (CC-22b and CC-23a)corresponds to more homogeneous oxygen isotope values. These, however, present locallyremarkable negative shifts, covariant with carbon isotope values, which suggest that diagenetic
events affected both carbon cycle (sulphate-reduction) and oxygen cycle (subsurface diagenesis).
The general behavior of the oxygen isotope curve points out to a decrease in temperatureof ocean waters from late Campanian to early Maastrichtian during the 2.7 Ma time spanrecorded in the cored section.

Quaternary and Miocene Thoracosphaera in the Ross Sea (77° S Latitutde)
Giuliana Villa 1 and Sherwood Wise 2
12

Cape Roberts Scientific Par, ITALY. E-mail: GeolOl@ipruniv.cce.unipr.it
Department of Geology, 4100 Florida State University, Tallahassee, FL 32306-4100 USA.
E-mail: Wise@gly.fsu.edu.

Ice-based drilling in the Victoria Land Basin of the southwestern Ross Sea during thefirst season of the Cape Roberts Project (October, 1997) has recovered Thoracosphaera (acalcareous dinoflagellate) in small but consistent numbers in Quaternary sediments (1.6-1.0 Ma
according to diatom stratigraphy) as well as in equally small numbers in lower Miocene
sediments (including their contained sedimentary clasts). No other calcareous nannofossils were
found throughout the 147-m core; similarly, no other nannofossils been have reported previously
from the Quaternary of the margins or shelves ofEast Antarctica. The Quaternary
Thoracosphaera occur as well-preserved fragments up to 40 microns in a peculiar 2-m-thick,carbonate-rich fossiliferous sequence that is essentially a hash of invertebrate macro fossil shells
within an otherwise clastic-rich glacial or glaciomarine sequence. Part of the material has been
winnowed and other parts not. The best preservation and more abundant occurrences of thesemicrofossils were recorded in the finest sediments, which is an unwinnowed mud. Two samples
from winnowed material were barren.
Thoracosphaerids have been described from the Eocene of the Ross Sea and are known tohave bloomed shortly after the KIT boundary event in the peculiar environment of theStrangelove oceans in several parts of the world. Like calcareous nannofossils, dinoflagellates(and presumably calcareous dinoflagellates) as a group prefer warmer waters.
As the late Neogene/Quaternary were times of rapid climatic change, such conditions
may have favored the presence ofthoracosphaerids as opposed to other calcareous
nannoplankton. The presence of thoracosphaerids in the Quaternary, therefore, could suggest
either a peculiar adaptation to this environment, due to their ability to develop cysts, or towarmer conditions at the time of their deposition, or a combination of both.

Recent Distributions of Calcareous Dinoflagellates in the South Atlantic and Their
Potential Use in Palaeoecology
Annemjek Yink, Karin Zonneveld and Helmut Willems
Fachbereich 5- Geowissenschaften, University ofBremen Postfach 33 04 40,
D-28334 BREMEN, GERMANY. E-mail: vink@micropal.uni-bremen.de; willems@micropal.uni-bremen.de

Dinoflagellates are generally unicellular algae and live in most aquatic environments.
Approximately 10% of all living dinoflagellate species produce geologically preservable cysts as
an important part of their life cycle. These cysts are generally organic walled and are extremely
resistant to degradation, although a few dinoflagellate taxa incorporate calcite into their cyst wall(i.e. the calcareous dinoflagellates). In addition, the calcareous walled vegetative coccoid
Thoracosphaera heimii is preserved in the sediment. As many cysts are species-specific, cyst
associations found in sediments are considered to represent the dinoflagellate community present
in the upper water column at the time of deposition. The spatial distribution of motile
dinoflagellates in the upper water column of the oceans is dependent on environmental factors
such as temperature, salinity, nutrient content and the availability oflight. As such, we cantherefore use fossil dinoflagellate cysts as tools for reconstructing palaeoenvironment,
palaeoclimatology, palaeoecology and palaeoceanography.
Even though the calcareous forms overwhelmingly dominate the total dinoflagellate cyst
flux into the sediment (concentrations of several millions of cysts per gram of sediment are notuncommon), the ecological information concerning these dinoflagellates is extremely limited andtheir use as palaeoenvironmental indicators has only started to develop in the last couple of years.
Recent studies suggest that enhanced abundances of calcareous dinoflagellates occur when the
productivity is low, i.e. in oligotrophic water conditions. However, a more detailed knowledge ofthe ecological preferences of each dinoflagellate species must be obtained. For these purposes, acomparison between calcareous cyst and Th. heimii distributions in the surface sediments fromdifferent regions ofthe South Atlantic and the environmental characteristics of the overlying
water column (i.e. temperature, salinity, nutrient content) is made in the scope of the current
study. In doing so, the effects of transport and preservation of cysts and Th. heimii should not be
overlooked (for example, calcite may partially or totally dissolve at depths below the lysocline or
Calcium Compensation Depth respectively). Studies as these provide a basic skeleton of
ecological information on which the analysis of Quaternary sequences should be based.

Microfossils Help in Deciphering a Complex Metamorphic and Paleogeographic Enigma
S. Volin, 1 Y Eshef, H. Kisch 1
1

Dept. of Geology and Mineralogy, Ben- Gurion University, Beer-sheva 84105, ISRAEL.
E-mail: yoram@mail.gsi.gov .il
2
Geological Survey oflsrael, 30 Malkhe Israel St., Jerusalem 9550, ISRAEL

Microfossils help of deciphering a complex metamorphic and paleogeographic enigma
The Hatrurim Formation in Israel forms a meta-sedimentary sequence, of colorful, mainly
reddish and black carbonates. Its mineralogy indicates a high-temperature thermal
metamorphism. It is commonly suggested that the unit formed from the thermal metamorphismof Campanian-Maastrichtian organic-rich layers that were combusted and burned, probably
during the Tertiary. The metamorphism probably occurred in foci of different sizes, in which
temperature in the center was the highest, whereas toward the margins of the focus, temperature
dropped. Until recently, most studies of the formation focused on the high- temperaturesmineralogy, and very little is known about the low-temperatures part of this event, since there arevery little mineralogical changes there, and the organic matter is almost completely missing. This
is why most studies in the past failed to reconstruct the shape and size of combustion foci. The
present research deals with the reconstruction of combustion foci and the metamorphic halo in
their margins, with a special emphasis on the reconstruction of the low-grade metamorphic
levels. Assuming that the composition and preservation ofthe microfossil assemblage in themetamorphic rock reflects the metamorphic process, optical and structural changes in organicand calcareous-walled microfossils were used to characterize the low- grade metamorphic
changes, and to draw isograde lines that reconstruct combustion foci. The authors developed orused existing optical methods in this paleometamorphic reconstruction: 1. Structural changes incalcareous nannofossils: the method is based on the rate of elimination of calcareous nannofossil
taxa during the metamorphic process. The following parameters are analyzed: Species diversity:a gradual decrease in species diversity with increasing metamorphism is observed, until only
nannofossil "ghosts" are left. Number of specimens: parallel to the decrease in species diversity,a decrease in number of nannofossil specimens is observed. Change in optical properties: As aresult of the metamorphic process, crystals undergo a reorganization. This results in the creationof new optical properties for calcareous nannofossil taxa. 2. Thermal Alteration Index (TAl): a
method based on the fact that organic matter in rocks (pollen, algae and spores) undergoes aprocess of darkening with the increasing thermal alteration. It is calibrated to the vitrinitereflectance method and can be used to detect low-temperature metamorphism in ahigh-resolution.

Jurassic Nannofossil Ecology and Environmental Cycles: Preliminary Results
E Benedjct Walswortb-Bell 1, Paul R. Bown 1 and Graham P. Weedon2
1

Department of Geological Sciences, University College London, Gower Street, London, WClE 6BT, UK.
E-mail: b.walsworth-bell@ucl.ac.uk; p.bown@ucl.ac.uk
2
Department of Geology, The University of Luton

A striking feature common to many Mesozoic pelagic sequences is the occurrence ofrhythmic bedding. Many of these cycles display periodicity at Milankovitch frequencies. Suchcycles in pelagic carbonates typically record variations in primary productivity. Fluctuations inmarine phytoplankton productivity are driven by shifting temperature and fertility gradients,
associated with the changes in global climate linked to metronomic perturbations in the Earth's
orbital geometry. Nannoplankton constituted an important component ofMesozoic
phytoplankton, and nannofossils are useful indicators of the physical and chemical conditions of
the surface waters in which they lived; nannofossil assemblages thus provide a basic tool in theinvestigation of such cyclicity.
The primary aim of this project is to examine the quantitative distribution of calcareous
nannofossils through Jurassic sedimentary sequences which exhibit clear environmentally-forced
cycles, in order to establish patterns of strati graphic distribution, and interpret these in terms of
surface-water environments. The Belemnite Marls Formation (Lower Pliensbachian) has beenchosen for initial study because of its well-documented sedimentary cyclicity (Weedon andJenkyns, 1990) and well-preserved nannofossil assemblages. Preliminary results, presented here,suggest that the cyclic nature of the lithology is essentially mirrored by in-phase changes innannofossil content (e.g. Schizosphaerella punctulata). Closely-sampled nannofossil
assemblages will be characterised in terms ofpalaeocommunity composition (e.g.
diversity/relative abundance of taxa). These datasets will be studied with reference tosedimentological!geochemical data, allowing ecological controls on specific taxa of Jurassic
nannofossils to be identified. They will also be subjected to time series analysis, in order to test
for the regular cyclicity that is diagnostic of orbital forcing. The identification ofMilankovitch
cycles and their frequencies may prove useful for high-resolution correlation of Jurassic
sequences across wide geographical areas. As such the results may potentially be of great
stratigraphical, as well as palaeoecological, value.

REFERENCE
Weedon, G.P. and Jenkyns, H.C. (1990) Regular and irregular climatic cycles and the Belemnite Marls(Pliensbachian, Lower Jurassic, Wessex Basin). J. Geol. Soc., London, 147, 915-918.

High Resolution Sequence Biostratigraphy with Calcareous Dinoflagellate Cysts,
Coccoliths and Foraminifera in the Cenomanian (Paris basin).
Jens Wendler, Kai-Uwe Grafe, Hartmut Mai, Helrnut Willems
Fachbereich Geowissenschaften, Universitiit Bremen, Postfach 33 04 40, 28334 BREMEN, GERMANY
e-mail: wendler@uni-bremen.de"

A high resolution study focusing on the distribution and absolute abundances of calcareous
dinoflagellate cysts was carried out to improve our understanding of Late Cretaceous orbital forcing(21 ka precession period) of chalk-marl sedimentary cycles. The results of this study were comparedto the distribution of coccoliths and planktic and benthic foraminifera.
The studied subcycle forms part of a Middle Cenomanian section ofthe London-Paris Basinand is composed of rhythmically alternating grey chalk with chalky marl and claystone. The section(Escalles, S of Calais, NW France) is situated in a central, outer shelf position ofthis epicontinental
basin. The complete Cenomanian/Turonian profile was interpreted in terms ofbiostratigraphy andsequence stratigraphy by ROBASZYNSKJ & AMEDRO 1993.
The aim of the present study is to investigate high frequency cycles with respect to thecalcareous dinoflagellate cyst content. The species spectra and the absolute abundances of specimens
were analysed in detail. Calcareous dinoflagellate cysts are subdivided into subfamilies according totheir wall structure. Orthopithonelloid forms show a strict radial calcite crystal orientation,
pithonelloid forms show a uniformly declined crystal orientation and obliquipithonelloid forms aremarked by a randomly oblique crystal orientation.
The investigated sedimentary cycle is, excluding two exceptions, dominated by pithonelloids(>95% of the assemblage).Therefore, the ratio Pithonella sphaerica/Pithonella ova/is was plotted,
showing clear fluctuations during the cycle. Low ratios are recorded in the basal marl, in the
culmination point of the chalk development (middle part of the cycle) and in the cycle top.
Pithonelloids are very rare at the base of the cycle, then rapidly increase in number to dominate theassemblage, and their relative abundances decrease to about 70 % only in the middle part of thecycle. There is a relation to the changes occuring within the oblique forms which are mainly
represented by Obliquipithonella pachystrata ZUGEL 1994 and the paratabulated forms
Cubodinellum renei KEUPP 1987 and Pentadinellum vimineum KEUPP 1987. The abundances of 0.
pachystrata ZOGEL 1994 peak in the middle part of the cycle. The cycle shows a general increase in
the absolute abundances of cysts in which certain peaks probably represent short term productivity
variations.
The data were compared to the lithological data of the cycle derived from plotting thepercentages of certain grain size fractions of the sediment. This plot clearly shows a gradualdevelopment of the cycle without abrupt changes in lithofacies. No signs of dissolution or dilution
have been recorded suggesting that these Milankovitch cycles may be interpreted as productivity
cycles. In addition, the data set was compared to the distribution of foraminifera and coccoliths. The
distribution patterns of these three groups, their relationship to one another and the various
environmental factors that are likely to have controlled these distribution patterns will be discussed.
REFERENCEROBASZVNSKI, F. & AMEDRO, F. (1993): Les falaises cretaces du Boulonnais. La coupe de references du Cap Blanc-Nez
dans un contexte sedimentaire global. Ann. Soc. Geol. du Nord, T 2 (2), 31 -44.

Modeling Biosphere-Geosphere Interactions
Paul Westbroek

Gorlaeus Laboratories, University ofLeiden, P.O. Box 9502, 2300 RA Leiden,
THE NETHERLANDS. E-mail: westbroek_p@rulgca.leidenuniv .nl

Life is a major geological force, and it is therefore impossible to understand the
dynamism of the earth without considering the role of the biota in global models. However, aflagrant contrast exists between the limitations of sound modelization and the dynamics of life in
the real world. In the first place, models must be simple, while life is complex and diverse. And
secondly, models can only operate over a limited range in time and space, while living systems
characteristically operate over a wide range of temporal and spatial scales.
This deep problem may nevertheless be solved, for three reasons: (1) order and simplicity
appears to emerge at distinct levels ofbiological organization; (2) uniformity of the biologicalorganization appears to underly biodiversity; and (3) instead of single models of
geosphere-biosphere interactions, nested suites ofhierarchical modules may be constructed, eachconcentrating on one particular level of organization. The exemplary role of the coccolithophore
Emiliania huxleyi as a model system for the study of global dynamics will be discussed in somedetail. In order to be useful, the results of this study must be generalized to the calcifying
plankton as a whole. Thus, a comparative investigation of important coccolithophore species is
an important component of this research.
A new type of research organization, required for the efficient execution ofinterdisciplinary studies such as on Emiliania will be discussed.

Geobiology, Definition, Organization and Some Representative ResearchPeter Westbroek 1, Bas Kooijman, Jan van Hinte, Patrizia Zivetl
1

Gorlaeus Laboratories, University ofLeiden, P.O. Box 9502, 2300 RA Leiden,
THE NETHERLANDS. E-mail: westbroek_p@rulgca.leidenuniv.nl
2
Geomarine Center, Vrije Universiteit Amsterdam de Boelelaan, 1085 1081HV AMSTERDAM,
THE NETHERLANDS. E-mail zivp@geo.vu.nl)

Geobiology is concerned with the role played by life in geodynamics over geologicaltime. Geophysics and geochemistry having reached maturity, the full scale implementation ofgeobiology is now in order. This composite poster explains the fundamental problem ofgeobiology and how it may be approached by coordinated modeling of geosphere-biosphereinteractions at the molecular, organismal, ecological and global levels of organization. Thisapproach is illustrated by two geobiological projects-- the Global Emiliania Modeling Initiative(GEM), with its sister CODENET, and UTE, the modeling program of a universal theoreticalecosystem.

Chirality and the KIT Boundary
Jeremy R Ymmg 1, Paul R. Bown2 and Andrew Howard2
1

Palaeontology Department, The Natural History Museum, LONDON, ENGLAND. E-mail: jy@nhm.ac.uk
2
Department. of Geological Sciences, University College LONDON, ENGLAND.
E-mail: p.bown@ucl.ac.uk; a.howard@ucl.ac.uk

Almost no heterococcoliths display pure radial ultrastructures. Instead most cycles of
elements show obliquity, curvature or imbrication which imparts a handedness or chirality to thestructure. For instance Calcidiscus coccoliths show clockwise curvature and imbrication of distal
shield elements. There is no obvious reason why an alternative, mirror-image, form with anticlockwise element curvature should not be developed but in practice it never appears to be. Thisconsistency of chirality within any one species appears to be a universal character ofheterococcoliths- it is well shown for instance by the consistency of bridge orientation inGephyrocapsa, of flange spiralling in Helicosphaera, and of arkhangelskiellid central area
structures. To test the consistency we have carried out a special survey of Emiliania huxleyi,
which shows, relatively subtle, chirality, in distal shield element obliquity, proximal shieldelement terminations, inner tube element imbrication and central area element curvature. Surveyof electron micrographs of several thousand specimens has failed to discover any examples ofreversed chirality. This consistency, and analysis of growth, indicate that chirality is a product of
the nucleation stage of coccolith growth and provides further evidence for precise regulation of
calcite nucleation in coccoliths.
The consistency of chirality means that it provides extremely useful additional taxonomic
characters. Perhaps the most interesting example of this is provided by the families
Chiastozygaceae (Mesozoic) and Zygodiscaceae (Cenozoic), both of which are muroliths with anouter rim cycle ofV-units and inner rim cycle ofR-units. These two groups have frequently been
linked and indeed are not distinguished in some classifications. However, in the Chiastozygaceae
the outer cycle shows clockwise imbrication whereas in the Zygodisceae it shows anti-clockwise
imbrication. On the basis of this we sugge.st that the Zygodiscaceae did not simply evolve from
Chiastozygaceae survivors of the KIT boundary event but rather were a homeomorphic groupwhich evolved after the KIT boundary.
Chirality is also a widespread feature among nannoliths; sphenoliths are the only apparent
major exception. This supports other evidence for the close connection, and probable homology
ofheterococcoliths and nannoliths. Holococcoliths are much less commonly chiral, one more
expression of the great differences between holococcolith and heterococcolith biomineralisation.

Cenomanian Nannofossils and Milankovitch Cyclicity
Jeremy R Young\ AndrewS. Gale 1, Matteo Tazzi 1, Paul R. Bown 2, and Dawn Windley12

Palaeontology Department, The Natural History Museum, LONDON, ENGLAND. E-mail: jy@nhm.ac.uk
Department of Geological Sciences, University College LONDON, ENGLAND. E-mail: p.bown@ucl.ac.uk

Chalk-marl alternations are characteristic of Cenomanian shelf sediments on an almost
global basis. Recent research has shown that these facies are direct expressions of precession-band
Milankovitch cyclicity (Gale 1995). Moreover these sequences can be correlated on a bed to bed
basis by using a combination of bed thickness variations, geochemical signals and biostratigraphy.
Correlation across Western Europe is now very well established (Gale 1995) and has recently been
extended to more distant sequences including in the Crimea.
The nannofossil distribution in the Anglo-Paris basin sequences has been studied by Windley(1995). This showed that there was no great change in assemblages between marls and chalks butthat the chalks consistently contained higher abundances of Zeugrhabdotus and Biscutum species
than the marls. By contrast Watznaueria showed an inverse distribution, being more abundant in themarls. This pattern cannot easily be interpreted as a preservational effect since the preservation is not
greatly variable and if anything is slightly better in the marls. Moreover Erba et a! (1992) recorded asimilar, but higher amplitude, pattern from the exceptionally preserved nannofloras of the Gault
Clay. Zeugrhabdotus and Biscutum have been widely interpreted as eutrophic indicators on a rangeof evidence (e.g. Roth & Krumbach 1986, Watkins 1989, Erba 1992); whilst Watznaueria has beeninterpreted as an oligotrophic indicator, or perhaps more reasonably, as a background mesotrophic
species. So, like Erba et al. (1992), we interpret the Zeugrhabdotus + Biscutum rich levels as
indicative of periods of higher productivity. The pattern can be conveniently summarised using a
productivity index: Log[(%Zeugrhabdotus + %Biscutum)I(%Watznaueria)]. An index ofthis typeprovides a cleaner signal than the abundance pattern of any single species or genus and circumvents
the closed sum constraint.
Study of the Crimean sections however reveals an inverse relationship, the productivity
index increases in the marls rather than the chalks. This not a priori difficult to explain since marls
could easily be associated with riverine nutrient input and so higher productivity. Indeed Watkins(1989) documented patterns of this type from the Greenhorn Basin. However the bed-by bed
correlation to UK sequences which show the inverse relationship raises interesting problems ofinterpretation and strongly suggests that even in the UK-type facies coccolith productivity is not thedominant mechanism responsible for lithological expression ofMilankovitch cyclicity.

REFERENCES
Erba, E. Castradori D., Guasti G., & Ripepe M., 1992: Calcareous nannofossils and Milankovitch cycles; the example of
the Albian Gault Clay Formation (southern England), Palaeogeography, Palaeoclimatology, Palaeoecology, 93(1-2), p. 47-69.
Erba E. 1992: Middle Cretaceous calcareous nannofossils from the western Pacific (Leg 129); evidence forpaleoequatorial crossings. Proceedings of the Ocean Drilling Program; scientific results; 129, p. 189-201.
Gale, A. S., 1995: Cyclostratigraphy and correlation ofthe Cenomanian stage in Western Europe. In, House, M. R. &Gale, A. S. (editors), Orbital forcing timescales and cyclostratigraphy, Geological Society Special Publications,85, p. 177-197.
Roth P. H. & Krumbach K. R. 1986: Middle Cretaceous calcareous nannofossil biogeography and preservation in the
Atlantic and Indian Oceans: implications for palaeoceanography. Marine Micropalaeontology, 10, 235-266.
Watkins D.K. 1989: Nannoplankton productivity fluctuations and rhythmically bedded pelagic carbonates of theGreenhorn Limestone (Upper Cretaceous) Palaeogeography, Palaeoclimatology, Palaeoecology, 74, 75-86.
Windley D. E., 1995: Calcareous nannofossil applications in the study of cyclic sediments of the Cenomanian. Unpubl.
PhD thesis University College London, 462pp.

Coccolith Fluxes in the Central Arabian Sea
Alexandra Zeltner
G.P.I. Tuebingen, Sigwart Strassel, D-72076 Tuebingen, GERMANY.
E-mail: alexandra.zeltner@uni-tuebingen.de.

In the central Arabian Sea (14°27,46'N, 64° 34,32'E) PARFLUX Mark VI time series
sediment traps (WG Prof. Ittekkot, University of Hamburg) were moored in 508 m (CAST shallow),
999 m (CAST middle), and 2986 m (CAST deep) water depth. Six presplits of CAST middle andseventeen presplits of CAST deep were available for nannoplankton analysis. Sampling of CAST
middle and deep started at November 1st, 1995 and ended at October 2nd and April 30th, 1997,
respectively. Sampling intervals were 26 days. Sample processing was modified after Andruleit(1997).
Coccospheres contributed only 1 % to the total coccolithophore flux. The average daily
fluxes at CAST-12 deep were 5.67 x 108 coccoliths m·2 d- 1 • Average daily carbonate flux rates were
9.80 mg m-2 d- 1 (= 4.33 g m·2 y· 1, November 1995 -April 1997). Elevated coccolith fluxes weredetected at CAST-12 deep during the inter-monsoon period in spring, 1996 and the ending
SW -monsoon, 1996. The maximum of coccolith fluxes coincided with the peak fluxes recorded in
the Somali Basin during upwelling relaxation 1993 (BROERSE in prep.).
Cocco1ith fluxes at CAST-12 middle ranged between 2.03-4.27 x 10 8 ind. m·2 d -1 • The
highest flux (4.27 x 108 ind. m·2 d" 1) coincided with the NE-monsoon 1996. The coccolith calcite flux
ranged between 3.82- 4.08 mg m·2 d -1• A total of 31 heterococco1ithophore taxa were recorded at
CAST-12 middle. Gephyrocapsa oceanica Kamptner and Emiliania huxleyi var. huxleyi (Lohmann)
Hay et Mohler were the most abundant species, contributing between 59 - 83 % to the total coccolithassemblage. Coccoliths of other species occurred in very low numbers.
Coccolith fluxes at CAST-12 deep ranged between 2.12-8.68 x 108 ind. m· 2 d -1• Highest
fluxes were recorded during the end ofSW-monsoon, 1996 (September, October 1996, 8.53- 8.68 x
10 8 ind. m·2 d" 1) and the intermonsoon period in spring, 1996 (April1996, 7.33 x 10 8 ind. m-2 d-1).
Lo~es~ coccolith fluxes occured during bo~hNE-ll!onsoon periods, 1996 and 1997, and durinf thebegmmng SW-monsoon, 1996. The coccohth calcite flux ranged between 3.99- 14.85 mg m· d -I. A
maximum of 45 hetero- and 1 holococcolithophore taxa were identified at CAST-12 deep. The mostabundant species at CAST-'12 deep was G. oceanica (50- 70 %). Together with E. huxleyi var.
huxley~ they contrib~ted 66 - 78 % to the total coccolith. asse~bla?e. G. ocear:~ca showed the highest
coccohth fluxes dunng SW-monsoon (2.83- 5.89 x 108 md. m 2 d-). The fam1hy ofthe
Coccolithaceae comprised between 10-24% of the total coccolith assemblage. During
SW-monsoon diversity became lowest while the highest coccolith fluxes were recorded. In contrast
to observations ofthe living coccolithophore assemblage the seasonal alteration of thecoccolithophore assemblage influenced by the monsoon could not be recorded in the coccolith

fluxes. Only the opportunistic species G. oceanica showed increasing values of coccoliths at
CAST-12 deep during the SW-monsoon 1996. In contrast, the coccoliths of the oligotrophic species
Umbellosphaera spp. increased during SW-monsoon. The coccolith flora showed a strong alterationin species diversity compared to observations of the living coccolithophore flora in the Arabian Sea
and represented the most resistant coccoliths (placoliths).
ACKNOWLEDGEMENT: We thank working group of Prof. V. lttekkot (University of Hamburg) providing for sediment
trap samples.
REFERENCES:
ANDRULEIT, H. 1997. Coccolithophore fluxes in the Norwegian-Greenland Sea: seasonality and assemblage alterations.
Marine Micropaleontology, 31, 45-64. BROERSE, A. T. C. Coccolithophore export production in response tomonsoonal upwelling off Somalia (northwestern Indian Ocean) (in prep.).

Export Production and Preservation of Coccolithophores from Upwelling andOligotrophic Areas.
Patrizia Ziveri
Geomarine Center, Free University Amsterdam, de Boelelaan 1085, 108IHV
Amsterdam, The Netherlands
E-mail: zivp@geo.vu.nl

A good way to monitor coccolithophore production is to study the fluxes recorded by
sediment traps deployed at different depths below the euphotic zone production. In the present
study, the export production ofCoccolithophores was determined from sediment trap samples
moored at 500m in Guaymas Basin, in the central Gulf of California, at 3700m in the Northeast
Atlantic and at 3000m in Bannock Basin, in the eastern Mediterranean and compared withcoccolith accumulation rates in the top sediment underneath the trap stations. The integration of
production, sinking and fossilisation -processes is fundamental for the understanding of thecoccolith record as paleoclimate proxy. In fact a serious limitation of this approach is thatfor large parts of the ocean floor no coccolith record is available, because the surface sediment islocated below the calcite compensation depth (CCD), moreover even above the CCD thereconstruction of the record could be by no means straightforward.
I will illustrate the problems by concentrating on three locations where the verticalcoccolith fluxes are quantified: the North Atlantic coccolithophore bloom-dominated, theoligotrophic eastern Mediterranean coccolithophore dominated and a coastal, upwelling area near
Gulf of California diatom boom-dominated. In the latter setting only 20 % of the originallyproduced coccoliths are preserved in the sediment. I shall present an hypothesis that may explain
the dramatic difference in preservation. Our results indicate that for different oceanic settings themodels must be adapted in order to arrive at reliable dynamical interpretations of the coccolith
record and to develop global models.

Coccolith CaC03 Actuo and Paleo-fluxes from the Eastern Mediterranean
Patrizia Ziveri 1, Arrian Rutten 2, and Cesare Corselli3
r .• "

1

Geomarine Center, Free University Amsterdam, de Boelelaan 1085, 1081HV, Amsterdam, The
Netherlands
E-mail:zivp@geo.vu.nl

2

Institute of Earth Sciences. Dept. of Geochemistry, University of Utrecht. 3508T A Utrecht, The
Netherlands
3
Dept. of Earth Sciences. University of Milan. via Mangiagalli, 34, 20133. Milan, Italy...
Coccolit,h · C~C0 3 actuo- fluxes are measured by sediment traps to quantify

carbonate export production. The comparison of coccolith CaC03 rain to the sea floor
and its preservation at sites above the calcite saturation horizon, in oxic and anoxic
conditions allows us to quantify and model calcium carbonate dissolution above thislevel. We present here the n>:sults obtained from a sediment trap deployment and surface
sediment investigations in the eastern Mediterranean. The eastern Mediterranean is asuitable recorder of global climatic variations. In this area the particle fluxes as well as
the deep pelagic biogenic sediment can be compared between oxic and anoxic conditions.
The study was carried out within MAST -Marflux and -Paleoflux European programs.
Two time-series sediment traps have been deployed from November 1991 throughAugust 1994 at 2900dbar a;n:i 3700dbar, respectively above and below the brine/normal
sea water interface in the Bannock Basin, central eastern Mediterranean, to allow
comparison under oxic aad anoxic conditions.
The annual coccolith, coccolith CaC03 and total CaC03 fluxes have been
compared with their accumulation rates in surface sediments in anoxic and oxygenatedsediments nea~ the trap site. Coccoliths are the major contributor to the carbonate flux inthe basin and are also the dominant phytoplankton group . The comparison of thesediment trap results with the coccolith accumulation rates and coccolithophore species
diversity show a very high preservation of coccolith CaC03 in the surface sediments ofboth oxic and anoxic environments.